Defendant-appellant Manuel Then (“Then”) appeals from a judgment entered in the United States District Court for the Northern District of New York (McAvoy, /.), convicting him, following a plea of guilty, of assorted narcotics offenses, and sentencing him principally to 210 months’ imprisonment. Then argues that (1) the district court engaged in impermissible double-counting in denying him credit for acceptance of responsibility and enhancing his sentence for obstructing justice, and (2) the treatment by the Sentencing' Guidelines of crack cocaine relative to powder cocaine violates the Equal Protection Clause of the United States Constitution. Because we conclude that both arguments lack merit, we affirm the judgment of the district court.
BACKGROUND
Then was charged in a four-count indictment on January 7, 1994 with: conspiring to distribute and to possess with the intent to distribute cocaine and cocaine base, in violation of 21 U.S.C. § 846; distributing cocaine base, in violation of 21 U.S.C. § 841; possessing cocaine with intent to distribute, in violation of 21 U.S.C. § 841; and attempting to possess cocaine base with intent to distribute, in violation of 21 U.S.C. § 841. Co-defendant Louis Felix (“Felix”) was charged in three counts of the indictment, but was not charged with distributing cocaine base.
Then pleaded guilty to all four counts of the indictment without entering into a plea agreement on March 16, 1994, one day following jury selection. During the plea allo-cution, defense counsel explicitly stated that Then was pleading guilty only to his own acts, but was not admitting that he acted in conjunction with Felix. Then agreed with the government’s characterization of the acts underlying his guilty plea: that an individual named Patrice McGill identified Then, who went by the name “Odli,” as his source of cocaine; that McGill explained that Then was supposed to bring eight ounces of powder cocaine to Albany and retrieve eight ounces of cocaine base on the following day; and that when Then was arrested “he had on his person approximately eight ounces of powder cocaine and he stated to [the] Special Agent ... that he was there to retrieve the cocaine base that was seized the day before.”
Two days later, Then testified on behalf of Felix at the latter’s trial. A jury acquitted Felix on all three counts charged. On cross examination during Felix’s trial, Then stated that he did not “come [to Albany] to retrieve eight ounces of cocaine base. [He] came to deliver the package ... to McGill.” At Then’s sentencing, the government asked the district court to deny credit for acceptance of responsibility and to enhance Then’s' sentence for obstruction of justice, based primarily on the disparity between Then’s re*466sponses at his plea allocution and his testimony at Felix’s trial. The district court agreed, but expressed concern that relying on the same conduct — his trial testimony — as a basis for both a denial of credit and an enhancement might constitute impermissible double-counting. Ultimately, the district court decided it did not, and, given Then’s total offense level of 36 and criminal history category 2, sentenced Then principally to 210 months’ imprisonment.
Then now appeals.
DISCUSSION
1. Double Counting
Then’s first argument on appeal is that the district court impermissibly double-counted in denying him credit for acceptance of responsibility and enhancing his sentence for obstruction of justice based on the same conduct. A district court does not engage in impermissible double-counting when it considers a single act that “is relevant to two dimensions of the Guidelines analysis.” United States v. Campbell, 967 F.2d 20, 25 (2d Cir.1992). Because the disparity between Then’s remarks at his plea allocution and at Felix’s trial evidences both a failure to accept responsibility and an attempt to obstruct justice, we reject his argument. See United States v. Echevarria, 33 F.3d 175, 179 (2d Cir.1994) (‘We reject Echevarria’s contention that the district court’s reliance on the same statement both to increase his sentence under § 3C1.1 and to deny a reduction under § 3E1.1 constitutes double-counting.”).
2. Sentencing Guidelines and Equal Protection
Then next claims that the treatment by the Sentencing Guidelines of crack cocaine (cocaine base) as the equivalent of 100 times as much powder cocaine, see U.S.S.G. § 2Dl.l(c), Drug Quantity Table, violates the Equal Protection Clause of the United States Constitution. He claims that there is no credible scientific evidence supporting the view that crack cocaine is more addictive or dangerous than powder cocaine, rendering the sentencing disparity irrational. Moreover, he argues that the 100:1 ratio impacts unfairly upon racial minorities, who statistically speaking are the primary consumers of crack cocaine, as opposed to powder cocaine, which is consumed primarily by non-minorities. See generally State v. Russell, 477 N.W.2d 886 (Minn.1991) (en banc). We have, however, recently rejected this argument. See United States v. Stevens, 19 F.3d 93, 97 (2d Cir.1994) (“we join six other circuits that have similarly held that the Guidelines’ 100 to 1 ratio of powder cocaine to crack cocaine has a rational basis and does not violate equal protection principles”). Even more recently, this Court has held that Congress did not act with discriminatory intent in adopting the sentencing ratio at issue. See United States v. Moore, 54 F.3d 92 (2d Cir.1995). We therefore reject Then’s contention.
In addition, we decline to accept the invitation by the concurrence to notify Congress that if it does not adopt the recommendation of the Sentencing Commission, this Court in the future might invalidate the sentencing ratio as unconstitutional. Just as we ordinarily do not issue advisory opinions, we should not suggest to Congress that it ought to adopt proposed legislation. Our role is limited to interpreting and applying the laws that Congress passes, and striking down those that we conclude are unconstitutional.
CONCLUSION
Accordingly, the judgment of the district court is affirmed.