United States v. Morales-Chaires, 430 F.3d 1124 (10th Cir. Dec. 7, 2005) (failure to grant illegal reentry defendant downward departure for which he would have been eligible in federal district where fast-track program was available was not unreasonable, given his extensive criminal history; statutory mandate to avoid unwarranted sentencing disparities was merely one of many factors court had to consider).