the effect of the violation cannot be ascertained. See Davis v. Georgia, 429 U.S. 122, 97 S.Ct. 399, 50 L.Ed.2d 339 (1976) (per curiam); Sheppard v. Maxwell, 384 U.S. 333, 351-352, 86 S.Ct. 1507, 16 L.Ed.2d 600 (1966). Like these fundamental flaws, which never have been thought harmless, discrimination in the grand jury undermines the structural integrity of the criminal tr F.3d 8, 17 (1st Cir.2000) (“If [an error] did constitute structural error, there would be per se prejudice, and harmless error analysis, in whatever form, would not apply.”); Becht v. United States, 403 F.3d 541, 549 (8th Cir.2005) (suggesting, but not deciding, that counsel’s failure to raise a structural error on appeal would constitute per se prejudice); McGurk v. Stenberg, 163 F.3d 470, 475 (8th Cir.1998) (<HOLDING>); United States v. Canady, 126 F.3d 352, 364
holding that the failure to recognize every possible legal argument did not render counsels performance constitutionally deficient holding that a defendant must show prejudice resulting from counsels deficient performance to prevail on an ineffectiveassistance claim holding that where counsels deficient performance resulted in structural error prejudice will be presumed recognizing that defendant must show 1 that counsels performance was deficient and 2 that counsels errors prejudiced the defense holding that counsels performance was deficient for failing to investigate readily available evidence of mental impairment