Can a variance for "co-defendant disparity" be reasonable?

Earlier today the Sixth Circuit in Jackson had some interesting dicta about reasonableness and the need to justify a non-guideline sentence in detail.  And this afternoon I just saw that the Second Circuit, in the unpublished decision of US v. Toohey, No. 04-4565 (2d Cir. May 23, 2005), has set forth some similar points:

Under the advisory Guidelines system recognized in Booker, the reasonableness of a sentence will depend, in large part, on the sentencing court's compliance with its statutory obligation to consider the factors detailed in 18 U.S.C. § 3553(a). These include the applicable Guidelines range as well as any pertinent policy statements issued by the Sentencing Commission. Further, because Booker did not excise § 3553(c) from federal sentencing law, a district court that does not sentence within the applicable Guidelines range must still provide a "specific" statement of reasons for its decision, both orally at the time of sentencing and in writing on the judgment of conviction.

After this notable language (which alone would seem to justify a published opinion), Toohey gets particularly interesting because of its discussion of what sorts of "unwarranted disparities" can be of concern to district courts under § 3553(a)(6).  This issue arose in Toohey because the district court justified a departure "by reference to a more lenient sentence imposed on an unrelated defendant."  Here's what the Second Circuit had to say about that:

Title 18 U.S.C. § 3553(a)(6) statutorily obligates a federal sentencing court to consider "the need to avoid unwarranted sentence disparities among defendants with similar records who have been found guilty of similar conduct." As we observed in US v. Joyner, 924 F.2d at 460-61, the unwarranted disparities that informed this statutory concern were not those between any two discrete cases or even between two defendants in the same case.  Rather, Congress's "objective was to eliminate unwarranted disparities nationwide." Id. at 460.  Joyner recognized that "[t]he method chosen by Congress to avoid unwarranted disparities is a guideline system that prescribes appropriate sentencing ranges for various combinations of facts concerning an offense and an offender and permits a sentencing judge to depart from the recommended range in unusual circumstances." Id.  Although Booker now requires us to substitute the word "recommends" for "prescribes" in the quoted observation, in all other respects, Joyner's construction of the role the Guidelines play in § 3553(a)(6) consideration remains the same.  Thus, a sentencing court does not reasonably satisfy its statutory obligation under § 3553(a)(6) when it only compares discrete cases or defendants.  Rather, to identify a reasonable sentence, § 3553(a)(6) expects a court to consider whether a defendant is favored or disfavored by a particular sentence "compared to all those similarly situated defendants." United States v. Joyner, 924 F.2d at 461 (emphasis added).FN 3

FN 3 Our attention to § 3553(a)(6) is not meant to suggest that provision should dominate the district court's sentencing analysis. On the contrary, the Sentencing Reform Act "requires judges" to consider the factors listed in all seven subparts of § 3553(a).  We focus on § 3553(a)(6) here because the district court based its Guidelines departure solely on the ground of sentencing disparity.  On remand, the court should consider all § 3553(a) factors in deciding whether to impose a Guidelines or non-Guidelines sentence.

The issue of whether a departure might be justified based on co-defendant disparity was fascinating and nuanced even before Booker came along.  Compare, e.g., US v. Caperna, 251 F.3d 827, 830-31 (9th Cir. 2001) (approving departure based on co-defendant disparity in some instances) with US v. Wong, 127 F.3d 725, 728 (8th Cir. 1997) (rejecting co-defendant disparity as a ground for departure).  The Booker remedy adds a layer to the co-defendant disparity onion by raising the possibility that co-defendant disparity might provide a basis for a variance, although the work of the Second Circuit in Toohey suggests that such a variance would not stand unless supported by other 3553(a) factors.  (Of course, 3553(a)(2)(A) calls for sentences that "promote respect for the law," and an argument can surely be made that co-defendant disparity undermines respect for the law.)