dissenting:
Appellants Oscar Anderson and Samuel Hogan asked the district court to grant a downward departure under § 5K2.0 of the Sentencing Guidelines1 from their sentences of 121 and 78 months, respectively, for possession with intent to distribute crack. cocaine. In support of these requests, both appellants argued that the findings in the Sentencing Commission’s Special Report to Congress on Cocaine and Federal Sentencing Policy (“Special Report,” reprinted in Anderson Joint Appendix at A-42) regarding the unfairness of the 100:1 eraek/cocaine sentencing differential constituted a mitigating circumstance warranting departure. The majority correctly points out that the Commission’s policy statement restricting § 5K2.0 departures to “atypical cases” would seem to rule out a departure request like this one, which rests on grounds that are common to an entire class of offenders. But I do not believe that the Commission’s policy statement on- atypicality should or can prohibit departure in this case. Although generally considered an authoritative interpretation of the Sentencing Guidelines, a policy statement does not bind federal courts if it violates the Constitution, a federal statute, or the underlying guidelines. Stinson v. United States, 508 U.S. 36, 45, 113 S.Ct. 1913, 1919, 123 L.Ed.2d 598 (1993). Here, the Commission itself has concluded that the crack/cocaine guidelines do not adequately reflect the relative culpability of crack offenders. A defendant sentenced under the current crack guidelines is therefore likely to receive a sentence which both the Commission and Congress admit is substantially greater than necessary to “reflect the seriousness of the offense” and “provide just punishment” — a result which violates § 3553(a) of the Sentencing Reform Act. 18 U.S.C. § 3553(a)(2) (1994). Since wooden adherence to the atyp-icality requirement in the face of these findings would prevent the district court from granting a departure even in the face of a violation of a federal statute, I do not see how it can be binding here and I conclude a departure is authorized.
In ruling that the policy statement on atypicality prohibited the district court from granting appellants a § 5K2.0 departure,2 the majority defends the requirement as a reasonable gloss on § 3553(b) of the Sentencing Reform Act. Section 3553(b), my colleagues contend, permits departure only when a defendant (or the government, in the case of an upward departure) establishes that he should *446not be sentenced within the otherwise applicable guidelines range because the facts of his case are so unusual as to make the offense substantially and meaningfully different from the “heartland” of eases on which the relevant guidelines range was based. The atypicality requirement serves the Act’s goal of uniform sentencing by forcing courts to abide by the Commission’s guidelines, rather than using their departure authority to make an end-run around them. In all but the most extraordinary case, I take no issue with this view that the atypicality requirement acts as a permissible constraint on how the courts may exercise their departure authority and appropriately operates to deny a § 3553(b) departure where the defendant proffers only “typical circumstances” in support of his request. Like any policy statement or official commentary issued by the Commission, we defer to the atypicality requirement as an “authoritative guide to the meaning of the applicable guideline.” Williams v. United States, 503 U.S. 193, 201, 112 S.Ct. 1112, 1119, 117 L.Ed.2d 341 (1992). In elaborating on this dictate, the Supreme Court has instructed us to review policy statements and official commentary which interpret or explain the guidelines with the same degree of deference accorded an agency’s interpretation of its own legislative rules — a standard of review somewhat more deferential than the Chevron-style deference we accord the guidelines themselves as the Commission’s interpretation of the Sentencing Reform Act. Stinson, 508 U.S. at 45, 113 S.Ct. at 1919 (quoting Bowles v. Seminole Rock & Sand Co., 325 U.S. 410, 414, 65 S.Ct. 1215, 1217, 89 L.Ed. 1700 (1945)); see also United States v. Smaw, 22 F.3d 330, 333 (D.C.Cir.1994) (“We owe the Sentencing Commission’s commentary on its own guidelines the same treatment as we afford ‘an agency’s interpretation of its own legislative rules.’ ” (quoting Stinson)). Since the Commission’s policy statement on atypicality explains how sentencing courts are to apply the various policy statements governing departures, see U.S.S.G. Ch. 1, Pt. A, § (4)(b), it strikes me as more like an interpretation of the guidelines, rather than a direct interpretation of the Sentencing Reform Act, and thus, like the official commentary in Stinson, reviewable as an agency’s interpretation of its own legislative rules. But regardless of whether the appropriate standard of review is that applied in Stinson or the less deferential standard employed in Chevron, my colleagues and I agree that the atypicality requirement must be respected and departures denied if the circumstances upon which a defendant relies are common to an entire class of offenders — except, however, in those rare instances where its application would violate the Constitution, a federal statute, or the underlying guidelines.
The majority’s .analysis of this case is flawed because it stops short of asking the critical question: whether these cases fit into that very narrow category of circumstances where a policy statement or official commentary is not binding upon a sentencing court because it violates constitutional or statutory dictates.3 In light of the findings in the Special Report, it seems to me that applying the atypicality requirement to deny departure authority would violate a federal statute — the Sentencing Reform Act itself. Section 3553(a) of the Sentencing Reform Act sets forth the factors a court must consider when sentencing under the guidelines, direct*447ing courts to impose a sentence which is “sufficient, but not greater- than necessary” to achieve the goals of sentencing.4 To guide the courts in determining when a sentence is “sufficient,” § 3553(a) lists four purposes of sentencing:
(2) the need for the sentence imposed—
(A) to reflect the seriousness of the offense, to promote respect for the law, and to provide just punishment for the offense;
(B) to afford adequate deterrence to criminal conduct;
(C) to protect the public from further crimes of the defendant; and
(D) to provide the defendant with needed' educational or vocational training, medical care, or other correctional treatment in the most effective maimer.
18 U.S.C. § 3553(a)(2). Although the Commission does not expressly provide a specific vehicle for weighing these purposes in the sentencing process it outlines, see, e.g., Kenneth R. Feinberg, The Federal Guidelines and the Underlying Purposes of Sentencing, 3 Fed.Sent.R, 326 (1991), it is clear from the legislative history of this provision that Congress took the four purposes set out in the law seriously, and intended sentencing courts to do so as well.5 In usual cases, it is reasonably assumed that the Commission’s guidelines adequately reflect these purposes. But that assumption falls apart in the exceptional situation where the Commission itself admits that its guidelines do not accomplish *448the four purposes of § 3553(a). To blindly adhere to the atypicality requirement even if doing so would plainly violate the mandates of § 3553(a) is to give no meaning at all to that provision — an interpretation which would be at odds with basic tenets of statutory construction. See, e.g., Babbitt v. Sweet Home Chapter of Communities for a Great Oregon, — U.S. —, —, 115 S.Ct. 2407, 2413, 132 L.Ed.2d 597 (1995) (expressing “reluctance to treat statutory terms as surplus-age”).
The nub of the problem here, of course, is that the Special Report is a startlingly forthright admission by the Sentencing Commission that its crack guidelines violate § 3553(a)’s instructions that a court impose a sentence “sufficient, but not greater than necessary” to “reflect the seriousness of the offense” and “provide just punishment.” In the Special Report, the Commission stated, inter alia, that there was “sparse empirical evidence” supporting the proposition that crack was 100 times more dangerous to society than cocaine. Special Report at 195. The Commission further stated that contrary to Congress’ intent to punish offenders in proportion to the quantity of drug sold, the 100:1 ratio resulted in higher penalties for street dealers, who are more likely to possess the drug in its crack form, than for suppliers, who are more likely to have larger amounts of the drug, but in its cocaine form: “Issues of ‘fairness’ or ‘just punishment’ — not to mention frustration of some congressional objectives — result when relatively low-level crack retailers receive higher sentences than the wholesale-level cocaine dealer from whom the crack sellers originally purchased the powder to make the crack.” Id. at 193. In summary, the Commission concluded that
[E]ven while agreeing that crack may be more harmful than powder cocaine,.... the Commission firmly concludes that it cannot recommend a ratio differential as great as the current 100-to-l quantity ratio. Several factors lead the Commission to [this] conclusion_ First, when Congress established the quantity ratio in 1986, there were no sentencing guidelines; rather, the guidelines took effect in 1987 and were not fully implemented until 1989. Accordingly, Congress had only the possibility of an enhanced ratio to look to in capturing, in a sentencing structure, the additional harms that legislators felt inhered in crack cocaine. Therefore, to the extent that the guidelines now provide a punishment for some of those same factors subsumed in the ratio, those factors generate an enhancement both through an increased ratio differential and through guideline adjustments.... Accordingly, if Congress believed that certain factors [such as carrying a gun or prior criminal activity] warranted a 100-to-l quantity ratio and if the subsequently adopted guidelines provided a punishment for some of those factors, then, as a logical matter, the ratio should be lowered by an amount commensurate with the extent to which these factors are addressed by the guidelines .... Another central basis for the Commission’s rejection of this ratio is the extreme anomalies in sentencing produced by such a high differential in penalties between two easily convertible forms of the same drug.... Similarly, although evidence suggests that the trafficking and use of crack cocaine have engendered more violence associated with marketing the drug than has powder cocaine, the evidence does not indicate that the increased level of violence and crime justifies a ratio as large as 100-to-l.
Id. at 196-97. Additionally, in the Commentary accompanying a proposed amendment which the Commission submitted to Congress that would have eliminated the sentencing disparity, the Commission stated that
[S]ufficient policy bases for the current penalty differential do not exist. Instead of differential treatment of crack and powder cocaine defendants based solely on the form of the drug involved in the offense, the Commission concluded that fairer sentencing would result from guideline enhancements that are targeted to the particular harms that are associated with some, but not all, crack cocaine offenses. Harm-specific guideline enhancements will better punish the most culpable offenders and protect the public from the most dangerous offenders, while avoiding blanket in*449creases for all offenders involved with the crack form of cocaine.
60 Fed.Reg. 25,074, 25,076 (1995).
These acknowledgments by the Commission itself — that crack sentences raise “[tissues of ‘fairness’ or ‘just punishment’” because they punish less culpable crack dealers far more severely than more culpable cocaine dealers and suppliers, and that no policy basis for the present 100:1 sentencing differential exists — make it impossible to square the crack guidelines with the sentencing purposes of § 3553(a).6 For this reason, I believe a district court is authorized to disregard the atypicality requirement and, though it should proceed cautiously in this largely unehartered terrain, to grant a departure if it determines that application of the crack guidelines to the case before it will, in fact, plainly violate § 3553(a). ■
Several courts have already followed a similar course in parallel situations, setting aside commentary or policy statements as inconsistent with the Constitution, federal statutes, or the guideline provisions to which they refer. See, e.g., United States v. Stevens, 66 F.3d 431, 434-36 (2d Cir.1995) (declining to follow commentary to U.S.S.G. § 2J1.7, which requires sentence enhancement for persons who commit an offense while on release from prison, on the grounds that the commentary is inconsistent with the underlying guideline and statutory provision); United States v. Powell, 6 F.3d 611, 613-14 (9th Cir.1993) (courts must ignore commentary to U.S.S.G. § 3A1.2 in situations where the underlying crime is felon in possession of a firearm, because in such circumstances the commentary and guideline.are inconsistent); United States v. Lamb, 6 F.3d 415, 420 (7th Cir.1993) (court not bound by commentary to U.S.S.G. § 3B1.3, “abuse of public trust” guideline, because it conflicts with guideline itself). One of our Third Circuit colleagues has gone even farther, suggesting that the statutory directive to impose a sentence “sufficient, but not greater than necessary” to meet the sentencing purposes set forth in § 3553(a) may even override the trial court’s otherwise unfettered discretion in deciding whether to grant a-, departure,7 and concluding that the district court may be required to. grant a departure under § 3553(b) if a sentence is “plainly unreasonable” in light of § 3553(a)’s' dictates. United States v. Denardi, 892 F.2d 269, 272 (3d Cir.1989) (Becker, J., dissenting). Cf. United States v. Darvern, 970 F.2d 1490 (6th Cir.1992) (en banc) (reversing panel’s decision that § 3553(a) requires courts to make an explicit deternlination in every case as to whether application of the guidelines is appropriate in light of the sentencing purposes set forth in the Sentencing Reform Act, before proceeding to calculate guidelines range and departures), cert. denied, 507 U.S. 923; 113 S.Ct. 1289, 122 L.Ed.2d 681 (1993).
Naturally, I do not suggest that a court should be permitted to depart whenever it decides that a sentence is greater than necessary to satisfy the purposes set forth in § 3553(a). Such a result would gravely undermine one of the central goals of the guidelines — restricting the discretion accorded sentencing judges, in the interests of eliminating unwarranted disparity in sentences. But this case is sui generis in the history of the guidelines. Here, the Commission itself has acknowledged that its crack guidelines bear no meaningful relationship to the culpa*450bility of defendants sentenced pursuant to them.8 To my knowledge, the Commission has never before made such an extraordinary mea culpa acknowledging the enormous unfairness of one of its guidelines. For this reason, authorizing departures based on the Special Report could not conceivably start courts down the slippery slope of granting departures every time a defendant claims the guideline for his type of offense is unfair. Nonetheless, I realize the consequences of my position. Permitting departures by sentencing judges based on the Commission’s Special Report has the potential for eroding the uniformity of sentences meted out to crack offenders. Although such a ruling would not require departures in the event a sentencing court found a plain violation of § 3553(a), a substantial number of district court judges might well find a departure appropriate, and they might not agree on how much to depart. The ensuing disruption in sentencing uniformity could be held in check, however, by limitations set on' the extent of such departures by the appellate courts on review or on an interim basis by the Commission itself. Additionally, I would not anticipate that authorizing departures based on the Special Report would interfere in any way with the ongoing efforts by Congress and the Commission to develop a permanent solution to this disparity; regardless of what significance the courts assigned to the Special Report in the short term, any resolution of the issue which did not violate the Constitution, federal law, or the guidelines would presumably bind federal courts from that point forward.
Imposing a criminal sanction on defendants is a grave matter — perhaps the most serious act in our judicial system, which appropriately surrounds it with a wide array of procedural protectiotis. Yet, ironically, if this were a run-of-the-mill administrative law case, I predict that we would not hesitate for a moment to vacate an agency’s legislative rule, if the agency itself admitted that the rule was arbitrary, capricious, unfair, and violative of a federal statute, and then documented that admission with credible evidence. Defendants like appellants Anderson and Hogan, faced with inordinately lengthy terms in prison, should be treated similarly. Although we must give heed to Congress’ goal of eliminating sentencing disparities in interpreting the Sentencing Reform Act, it seems to me the ultimate triumph of form over substance to base prison sentences on guidelines which have now been repudiated as irrational by the authors of those guidelines themselves. I would therefore find there is authority on the part of a district court to depart from the current guidelines governing crack cocaine offenses.
. Section 5K2.0 authorizes departures if "the court finds that an aggravating or mitigating circumstance exists that was not adequately taken into consideration by the Sentencing Commission in formulating the guidelines and that should result in a sentence different from that described.” U.S.Sentencing Guidelines ("U.S.S.G.") § 5K2.0 (quoting 18 U.S.C. § 3553(b)).
. Judge Williams offers several other reasons for affirming the district court’s determinations in both appellants’ cases that it lacked authority to grant a § 5K2.0 departure. See Majority opinion ("Maj. op.”) at 438-42. Because Judge Tatel’s concurrence identifies the atypicality requirement as the fatal flaw in appellants’ departure requests, see Tatel, J., concurring in part and concurring in the judgment, at 442, I take this point to. be the grounds upon which a majority of this panel agrees the district court should be affirmed.
. I do not disagree with the majority's conclusion that appellants’ requests for departure fail the atypicality test. As compared with circumstances present in other crack offenses, the circumstances for which appellants seek departure are typical; the conclusions of the Special Report will apply as réadily to the majority of crack cases as to the two cases before us. Appellants’ arguments to the contrary are not availing. They claim that while the findings of the Special Report may be a circumstance common to all crack cases, they are not common to all federal drug offenses, which obviously include drugs other than crack. See Anderson Reply Br. at 6. This characterization inevitably raises the question, "iypical, as compared to what?” The answer implicit in the majority's opinion seems the right one: typical, as compared to other similar offenses. Since each type of controlled substance listed in the guidelines presents fairly unique risks of harm to the user and the surrounding community, the relevant group of similar offenses for determining the lypicality of a circumstance is possession or sale of the same controlled substance which the defendant possessed or sold, not possession or sale of all controlled substances. Appellants’ stated grounds for departure are typical, then, because they are common to all crack offenses, even if not to all federal drug offenses.
. As my colleague Judge Tatel points out, § 3553(a)’s mandate to sentencing courts cannot be read in isolation from § 3553(a)(4), which instructs courts to consider the applicable guidelines range as one of the factors in determining sentence, as well as § 3553(b), which states that a sentencing court "shall impose a sentence ... within the [guidelines] range," unless it finds an aggravating or mitigating circumstance warranting departure. See Tatel, J., concurring, at 443-44. Judge Tatel would interpret § 3553(b) as governing the question of whether a court must sentence within the applicable guidelines range, and § 3553(a) as relevant only to the question of where within that range the sentence should be. Id. I see the intended interplay between these two provisions differently. Although a sentencing court should consider the factors set forth in § 3553(a) in determining where within the guidelines range a sentence should fall, those factors are also relevant to whether a departure under § 3553(b) is warranted in the first place. See United States v. Clark, 8 F.3d 839, 842 (D.C.Cir.1993) ("To qualify as ‘mitigating’ a circumstance must be linked to one of the stated purposes of sentencing, i.e., just punishment, adequate deterrence, public protection, or rehabilitation.” (citing § 3553(a)(2) and United States v. Mason, 966 F.2d 1488, 1494-97 (D.C.Cir.), cert. denied, 506 U.S. 1040, 113 S.Ct. 829, 121 L.Ed.2d 699 (1992))). And just as with any other statutory provision, § 3553(a) is also relevant in deciding if application of a particular guideline, policy statement, or official commentary of the Commission — here, the policy statement on "atypicality” — is inappropriate because it would violate the Constitution or a federal statute.
. In its section-by-section analysis of amendments to the Sentencing Reform Act, the House set forth its understanding of § 3553(a):
Section 3553(a) as enacted by the Sentencing Reform Act of 1984 requires that the court (1) consider several factors, including the purposes of sentencing, and (2) “impose a sentence sufficient, but not greater than necessary, to comply with” the purposes of sentencing. Thus, if the court finds that the sentence called for is greater than necessary to comply with the purposes of sentencing, section 3553(a) would seem to require the court to impose a more lenient sentence.
Such an interpretation, it might be argued, is inconsistent with the Sentencing Reform Act’s intention to limit judicial discretion in sentencing. That argument, however, is not convincing. The Sentencing Reform Act of 1984 limited, but did not eliminate, judicial sentencing discretion. Section 3553(a) does not give the court unlimited discretion in sentencing, but rather authorizes the court to depart from the guidelines only if the court finds that the sentence called for by the guidelines is greater than necessary to serve the purposes of sentencing.
133 Cong.Rec. 31947 (Nov. 16, 1987). In fact, the House analysis of .§ 3553(a) goes even farther, suggesting that it may provide independent grounds for departure. Id. For additional remarks contemporaneous with passage of § 3553(a), see S.Rep. No. 225, 98th Cong., 1st Sess. 52 ("The bill requires the judge, before imposing sentence, to consider the history and -characteristics of the offender, the nature and circumstances of the offense, and the purposes of sentencing. He is then to determine which sentencing guidelines and policy statements [and mitigating circumstances] apply to the case.”); 68 ("each of the four stated purposes should be considered in imposing sentence in a particular case”); 75 (same); 77 ("The intent of subsection (a)(2) is ... to require that the judge consider what impact, if any, each particular purpose should have on the sentence in each case”) (1983), reprinted in 1983 U.S.C.C.A.N. 3182.
. Judge Williams maintains that if this conclusion is correct, then Congress sent "rather contradictory signals” by enacting both mandatory mínimums with a ratio of 100:1, and a standard for evaluating sentences (§ 3553(a)) which that very ratio arguably violates — implying that such a construction of § 3553(a) cannot possibly be correct. That argument ignores the chronology of these events. Congress enacted both §'3553(a) and the mandatory mínimums before the research data which informed the Commission’s findings in its Special Report became available. Although that research might indicate that the mandatory mínimums, as passed by Congress, violate another statutory directive — the sentencing instructions contained in § 3553(a)— the two provisions were not in conflict at the time of enactment. The fact that Congress passed mandatory mínimums, then, has no bearing on whether it intended § 3553(a) to operate as a substantive sentencing standard.
. A district court’s exercise of its discretion to deny departure is unreviewable unless the record indicates that the judge mistakenly thought she lacked authority to grant a departure. United States v. Foster, 988 F.2d 206, 208 (D.C.Cir.) (citations omitted), cert. denied, 508 U.S. 945, 113 S.Ct. 2431, 124 L.Ed.2d 651 (1993).
. Judge Williams claims that a report authored and submitted to Congress by the Commission stands on exactly the same footing as “a report by a learned society.” Maj. op. at 440. My colleague’s position on this issue, quite frankly, makes no sense to me. Although it is true that a court may consider only the guidelines themselves, policy statements, and commentary in determining to what extent the Commission has "adequately considered” a circumstance, see § 3553(b), this provision certainly was not meant to bar judicial consideration of other statements by the Commission for purposes of identifying whether there were significant circumstances the Commission should have hut did not consider. Cf. Tatel, J., concurring, at 443-44 (“such reports may point out a factor that courts should examine as a possible mitigating or aggravating circumstance”). That is, the courts may look to Commission statements other than those listed in § 3553(b) to ascertain what circumstances are relevant to formulation of a guideline, but then must confine its inquiry to the § 3553(b) sources when determining the adequacy with which the Commission considered those circumstances. One would think such consideration would be mandatory, not prohibited; surely the Commission as a data collection body must have significant expertise concerning the impact of its own guidelines, more so than an outside organization. In any event, this rule (whatever its proper construction) places no constraints on the use of other statements by the Commission for the purpose of determining whether a sentence would plainly violate § 3553(a), and thus is inapposite here.