The State appeals the grant of Nebraska inmate Randall S. Whitmore’s petition for a writ of habeas corpus. The district court held that the Nebraska trial court violated Whitmore’s Sixth Amendment right to the effective assistance of counsel when it failed to inquire whether Whitmore had waived his trial counsel’s obvious conflict of interest. The State argues that the district court erred in excusing Whitmore’s procedural default of this claim under the “fundamental miscarriage of justice” exception to the cause and prejudice standard. See Coleman v. Thompson, 501 U.S. 722, 750, 111 S.Ct. 2546, 2565, *1428115 L.Ed.2d 640 (1991). We agree and therefore reverse.
Whitmore seeks federal habeas relief on two grounds: first, that trial counsel James Davis had an actual conflict of interest at Whitmore’s trial that adversely affected counsel’s performance; and second, that Douglas County Judge Paul J. Hickman erred in failing to hold a hearing, prior to Whitmore’s trial, to consider Davis’s obvious conflict of interest. Whitmore raised both claims in a state postconviction proceeding, but the Supreme Court of Nebraska concluded they were procedurally barred because Whitmore and his new appellate counsel knew of the conflict yet did not raise these issues on direct appeal. See State v. Whitmore, 238 Neb. 125, 469 N.W.2d 527, 531-32 (1991).
Whitmore then commenced this proceeding. After a hearing, the district court granted the writ. The court agreed that Whitmore’s federal habeas claims were procedurally defaulted in state court1 and further concluded that Whitmore did not show cause to excuse this default. However, the court held that the claims were not procedurally barred because they fell within the fundamental miscarriage of justice exception. The court reasoned that this exception is “akin” to the prejudice prong of the ineffective assistance of counsel standard under Strickland v. Washington, 466 U.S. 668, 104 S.Ct. 2052, 80 L.Ed.2d 674 (1984), and that such prejudice must be presumed once a defendant shows “that an actual conflict of interest adversely affected his lawyer’s performance.” Cuyler v. Sullivan, 446 U.S. 335, 350, 100 S.Ct. 1708, 1719, 64 L.Ed.2d 333 (1980).2 Turning to the merits, the district court held that Whitmore was entitled to habeas relief because Judge Hickman failed to inquire whether Whitmore had waived attorney Davis’s conflict of interest.
On appeal, the State argues that the district court erred in applying the fundamental miscarriage of justice exception and in concluding that Whitmore’s Sixth Amendment rights were violated by Judge Hickman’s failure to inquire.3 Because we agree with the State that Whitmore’s claims are procedurally barred, we do not reach the merits of those Sixth Amendment claims.
1. Whitmore argues that we need not reach the fundamental miscarriage of justice exception because the district court erred in ruling that he did not establish cause for his procedural default. We dis*1429agree. After his conviction, Whitmore retained different counsel for sentencing and still other counsel for his direct appeal. Both lawyers were aware of attorney Davis’s conflict of interest, discussed that issue with Whitmore, but did not raise it either at sentencing or on direct appeal. In the district court, Whitmore argued that appellate counsel were ineffective for defaulting the issue on direct appeal. On appeal he argues that trial counsel Davis was ineffective for failing to place the facts regarding his conflict in the trial record so that it could be effectively raised on direct appeal.
We generally do not consider arguments raised for the first time on appeal. See Warden v. Wyrick, 770 F.2d 112, 114 (8th Cir.), cert. denied, 474 U.S. 1035, 106 S.Ct. 600, 88 L.Ed.2d 579 (1985). But in any event Whitmore’s arguments must fail. Counsel’s failure to raise an issue on appeal is not the type of cause that excuses a procedural default unless counsel’s performance was constitutionally ineffective under Strickland. See Coleman, 501 U.S. at 752-55, 111 S.Ct. at 2566-67. We agree with the district court that Whitmore has failed to prove ineffective assistance of counsel; in particular, his appellate counsel’s studied decision not to raise the conflict issues on direct appeal was within the broad range of professional competence Strickland permits. Moreover, since Whitmore did not raise these ineffective assistance claims in the state courts, we doubt whether they may be raised for the first time in federal court to show cause for his procedural default of the conflict of interest claims here at issue. See Murray v. Carrier, 477 U.S. 478, 488-89, 106 S.Ct. 2639, 2645-46, 91 L.Ed.2d 397 (1986). Thus, as the district court recognized, Whitmore’s federal habeas claims are procedurally barred unless his default is excused under the fundamental miscarriage of justice exception.
2. The district court made two critical errors in applying the fundamental miscarriage of justice exception. First, the court erred in equating this exception with the prejudice prong of Strickland. Prejudice under Strickland is one component of the ineffective assistance inquiry. The fundamental miscarriage of justice exception, on the other hand, is “a gateway through which a habeas petitioner must pass to have his otherwise barred constitutional claim considered on the merits.” Herrera v. Collins, — U.S. -, -, 113 S.Ct. 853, 862, 122 L.Ed.2d 203 (1993). To fall within the exception a petitioner must make “a proper showing of actual innocence.” Id. — U.S. at -, 113 S.Ct. at 862. See also United States v. Olano, — U.S. -, -, 113 S.Ct. 1770, 1779, 123 L.Ed.2d 508 (1993) (“the term ‘miscarriage of justice’ means that the defendant is actually innocent”). The required showing is rigorous:
[T]he “actual innocence” exeeption[] applies only where the habeas petitioner demonstrates by clear and convincing evidence that, but for the alleged constitutional error, no reasonable juror would have found the petitioner guilty of the crime of which he was convicted.
Wallace v. Lockhart, 12 F.3d 823, 827 (8th Cir.1994), citing Sawyer v. Whitley, — U.S. -, ---, 112 S.Ct. 2514, 2517-18, 120 L.Ed.2d 269 (1992). This standard is neither akin to the prejudice prong of Strickland,4 nor may it be disregarded in the case of procedurally defaulted constitutional claims that would otherwise require no showing of prejudice.
Second, the district court erred in failing to apply the actual innocence exception separately to each of Whitmore’s procedurally defaulted claims. The district court granted the writ on the ground that Judge Hickman failed to inquire whether Whitmore knowingly waived his attorney’s conflict of interest. But the court did not apply the actual innocence exception to that claim. Rather, it excused Whitmore’s procedural defaults on the general ground that a conflict of interest claim requires no showing that the conflict prejudiced the defendant at trial.
*1430For the foregoing reasons, we must now determine, with respect to each of Whit-more’s claims, whether he has shown “by clear and convincing evidence” that but for the alleged constitutional error no reasonable juror would have found him guilty. Sawyer, — U.S. at -, 112 S.Ct. at 2525. We consider this issue de novo, as the Supreme Court clearly did in Sawyer.
3. For the first procedurally defaulted claim, the actual innocence question is whether no reasonable juror would have convicted Whitmore but for Judge Hickman’s failure to inquire, prior to Whitmore’s trial, into the propriety of attorney Davis representing Whitmore despite his apparent conflict of interest. To meet his burden on this issue, Whitmore must present clear and convincing evidence that, if that inquiry had been made, (i) he would have emerged with different trial counsel, and (ii) the outcome of the trial would have been different. A review of the record reveals that Whitmore has failed to meet the first of these two burdens.
Whitmore and John White were separately charged with unlawfully possessing the same drugs, which the police found in the trunk of a brown Plymouth Valiant. At the outset, Whitmore and White were separately represented. Attorney Davis represented White and successfully opposed the State’s motion to consolidate the two cases by arguing that the defendants might have antagonistic defenses.
White’s case was tried first to Judge Hickman without a jury. On the eve of Whit-more’s trial, with White’s case still under submission to Judge Hickman, Whitmore’s counsel resigned and three other attorneys declined to represent him. Whitmore then asked Davis for help. After noting the conflict issue and clearing the conflict with White, Davis agreed to represent Whitmore. Whitmore obviously knew of Davis’s conflict of interest — he was in court when the State’s motion to consolidate was argued — but chose to have Davis represent him. Had Judge Hickman held a hearing and explained the implications of Davis’s conflict on the record, would Whitmore have refused Davis’s services, or would he have waived the conflict? Whitmore’s extensive factual showing in both his state and federal postconvietion proceedings is totally silent on this critical question.
Virtually conceding that he would have attempted to waive the conflict, Whitmore argues on appeal that Judge Hickman “should have been obligated to refuse to accept any express waiver” of the conflict. He cites Wheat v. United States, 486 U.S. 153, 108 S.Ct. 1692, 100 L.Ed.2d 140 (1988), but Wheat simply held that a trial court “must be allowed substantial latitude in refusing waivers of conflicts of interest.” 486 U.S. at 163, 108 S.Ct. at 1699. Wheat also reaffirmed that counsel’s multiple representation does not always violate the Sixth Amendment and that courts “must recognize a presumption in favor of [the defendant’s] counsel of choice.” Id. at 164, 108 S.Ct. at 1700. Thus, Wheat confirms that Judge Hickman had substantial discretion in dealing with attorney Davis’s conflict of interest, and the actual innocence exception requires us to explore how he likely would have exercised that discretion had he conducted a pretrial hearing on the issue.
Had Judge Hickman conducted the pretrial inquiry that the district court found lacking, he would have recognized that the separate trials of White and Whitmore had “significantly reduced the potential for a divergence in their interests.” Cuyler, 446 U.S. at 347, 100 S.Ct. at 1718. With White’s trial completed, the only potential conflict remaining for Whitmore’s jury trial was that attorney Davis in defending Whitmore might be reluctant to “point the finger” at his other client, White, in front of Judge Hickman, who still had White’s case under submission. This is a legitimate concern. But we know that Judge Hickman, a jurist with twenty five years experience, was aware of the conflict and obviously believed that Davis could try Whitmore’s case to a jury without prejudicing his own consideration of White’s case. In these circumstances, we conclude that Whitmore has failed to prove by clear and convincing evidence that, had Judge Hickman conducted the missing inquiry, he would have rejected Whitmore’s waiver of the conflict and removed Davis as Whitmore’s trial counsel.
Unable to establish that a pretrial inquiry would have resulted in attorney Davis’s re*1431moval, Whitmore has no evidence that his subsequent trial would have resulted in a jury finding of actual innocence. Therefore, his failure to inquire claim, the claim upon which the district court granted habeas relief, is proeedurally barred.
4. There remains Whitmore’s second proeedurally defaulted claim — that his Sixth Amendment right to the effective assistance of counsel was violated because attorney Davis labored under an actual conflict of interest at trial. To prevail on the merits of this claim, Whitmore must show that the conflict adversely affected counsel’s performance. See Cuyler, 446 U.S. at 350, 100 S.Ct. at 1719. However, to excuse his procedural default of this claim under the actual innocence exception, Whitmore must prove by clear and convincing evidence that, but for Davis’s conflict, no reasonable juror would have found Whitmore guilty.
Whitmore’s theory is that, since Judge Hickman had not yet rendered a verdict in White’s ease, attorney Davis refrained from pointing the finger at White in Whitmore’s defense. The trial record reveals a number of problems with that theory. First, guilt in this case was not an either/or proposition; the State maintained that White and Whit-more were confederates and both were guilty. The drugs were found in the Valiant, which was parked far from the residences of both White and Whitmore. White and Whit-more were separately arrested two days later. White was carrying identification in the name of the fictitious registered owner of the Valiant; Whitmore was in possession of keys for that ear. It was undisputed that White and Whitmore were business associates. Prior surveillance had linked White directly to the Valiant. The State persuaded the jury that Whitmore, too, was linked to the drugs found in that vehicle.
Second, it appears that attorney Davis did point the finger at White at Whitmore’s trial. Counsel’s opening and closing statements were not transcribed, so the trial record does not reveal the relative emphasis given this point. But Davis testified that he told the jury in his opening statement that the drugs belonged to John White:
I said pure and simple that these drugs were not Randy Whitmore’s drugs; they were John White’s drugs. The evidence is going to show that John White was a friend; that he helped Randy in his businesses ....
Davis’s original trial notes corroborate that testimony. Further corroboration is found in a colloquy outside the jury’s presence, in which Davis argued to Judge Hickman:
The defendant has maintained from the beginning that that dope and narcotics found in the 1971 Valiant was not his and belonged to John White. The State’s theory of their ease ... is that that dope belonged to John White and Randy Whit-more .... that Randy Whitmore was the boss and John White was a mule and.... that John White allegedly worked for Randy Whitmore and they were both engaged in drug dealing.
We also note that Davis, while cross examining one of the state’s witnesses, reminded the jury that it was John White’s fingerprints that were found on items in the Valiant.
Third, we have carefully reviewed the trial tactics that Whitmore says an unconflicted lawyer would have done differently — calling additional witnesses and introducing additional evidence linking White to the drugs— as well as Davis’s explanation of his own strategy. Most of the alleged omissions would not have farther implicated John White and are therefore of little relevance to the “but for” issue under consideration. The most significant omissions were not calling John White or Whitmore as defense witnesses. Davis gave a rational explanation for not calling these witnesses. Whitmore failed to show that White was willing to testify and did not explain why the testimony of either would have changed the outcome of the trial.
Weighing all of these factors together, we conclude that Whitmore has fallen far short of proving by clear and convincing evidence that, but for Davis’s conflict of interest at trial, the jury would not have found him guilty. Accordingly, this claim, too, is procedurally barred.
For the foregoing reasons, the judgment of the district court is reversed and the case is remanded with instructions to dismiss Whit-*1432more’s petition for a writ of habeas corpus. Appellee’s motion to dismiss the appeal is denied.
.Judge Heaney’s dissent is founded on his conclusion that Whitmore’s actual-conflict-of-interest claim is not procedurally barred because the Nebraska Supreme Court "arbitrarily held that Whitmore had defaulted” the issue by not raising it on direct appeal. This question is not properly before us, as it was neither considered by the district court nor argued by Whitmore on appeal. In any event, we disagree with Judge Heaney’s conclusion. The Nebraska Supreme Court discussed at length its reasons for holding this claim procedurally barred. See 469 N.W.2d at 531-32. It cited in support of this ruling State v. Pope, a case in which a conflict-of-interest claim was raised and considered on direct appeal, see 211 Neb. 425, 318 N.W.2d 883, 885-87 (1982), and then raised again in a postconviction petition based upon alleged additional evidence, see 218 Neb. 361, 355 N.W.2d 216 (1984). In Pope, the Nebraska Supreme Court held the postconviction claim procedurally barred because the new evidence was not material, 355 N.W.2d at 218, not merely because the claim had previously been raised on direct appeal. This significantly reduces or eliminates the Catch 22 dilemma posited in Judge Heaney's dissent. Thus, the Nebraska Supreme Court in Whitmore reasonably construed its earlier decision in Pope as requiring a defendant to at least attempt to raise a known issue of actual conflict on direct appeal. Whit-more failed to do that and therefore his postcon-viction claim was procedurally barred.
. We note in passing that, while the district court correctly stated the holding in Cuyler, it never explained how attorney Davis’s conflict affected his performance at Whitmore's trial. In Whit-more’s state postconviction proceeding, Judge Hickman expressly held that Whitmore had failed to prove that Davis's conflict of interest adversely affected his performance at trial.
. Whitmore argues that Avery waived his right to appeal by failing to object to the magistrate's report and recommendation. We disagree. In Thomas v. Arn, 474 U.S. 140, 155, 106 S.Ct. 466, 474-75, 88 L.Ed.2d 435 (1985), the Supreme Court held "that a court of appeals may adopt a rule conditioning appeal, when taken from a district court judgment that adopts a magistrate’s recommendation, upon the filing of objections with the district court identifying those issues on which further review is desired.” We have not adopted such a rule. See Taylor v. Farrier, 910 F.2d 518, 520 (8th Cir.1990); Nash v. Black, 781 F.2d 665, 667 (8th Cir.1986).
. "If a showing of actual innocence were reduced to actual prejudice, it would allow the evasion of the cause and prejudice standard.... In practical terms a petitioner would no longer have to show cause, contrary to our prior cases.” Sawyer, - U.S. at - n. 13, 112 S.Ct. at 2522 n. 13.