discussed Cited "see" George Paul Skinner v. United States See Brown, v. United States, 311 F.3d 875, 878 (8th Cir.2002) (counsel’s decision not to raise issue unsupported by then-existing precedent did not constitute ineffective assistance), cert. denied, 540 U.S. 891 , 124 S.Ct. 229 , 157 L.Ed.2d 165 (2003); Nguyen v. United States, 114 F.3d 699, 703-04 (8th Cir.1997) (ineffective-assistance claim in guilty plea context).