court has not only the authority, but the obligation under § 3553(a)(6) to eliminate the sentencing disparities that result from fast-track programs. This Circuit has considered and rejected this argument. In United States v. Hernandez-Fierros, 453 F.3d 309 (6th Cir.2006), the defendant argued that the district court should have sentenced him below the Guidelines range in order to avoid imposing a sentence disparate from those imposed in districts with fast-track sentencing programs. Id. at 311. We disagreed, and joined several other circuits in holding that any disparity created by the fast-track program “does not run counter to 3553(a)’s instruction to avoid unnecessary sentencing disparities.” Id. at 314. See also, United States v. Martinez-Martinez, 442 F.3d 539, 543 (7th Cir.2006) (<HOLDING>); United States v. Sebastian, 436 F.3d 913, 916
holding that crackpowder disparity was constitutional stating that ujntil the en banc court of this circuit the us supreme court or congress itself accepts this assertion of disparity and finds it untenable challenges to the sentencing guidelines based on the disparity between sentences for crack cocaine and powder cocaine will continue to fail holding that district court plainly erred when it decided to impose a sentence comparable to a fasttrack sentence where the defendant did not enter into a fasttrack plea agreement holding that the law allows the government to offer reduced sentences in exchange for assistance even if it results in sentences of such disparity as would strike many as unfair holding that any disparity between the defendants sentence and sentences imposed in fasttrack districts was considered appropriately as a single and not controlling factor holding that the sentence disparities arising from fasttrack programs do not make  the defendants sentence unreasonable