Whether as-applied constitutional challenges to statutes of conviction are waived by an unconditional guilty plea, and the standard of review

QUESTIONS PRESENTED Following an unconditional guilty plea, Mr. Bacon was convicted federally of a non-violent, wholly intrastate sale of a handgun and wholly intrastate possession of a handgun with an obliterated serial number in Michigan. The only basis to federally prosecute Mr. Bacon was because the two firearms had, at some point in time, crossed state lines. The questions presented are: I. Consistent with Class v. United States, 583 U.S. __, 138 S.Ct. 798 (2018), are as-applied constitutional challenges to statutes of conviction waived by an unconditional guilty plea, and is the standard of review de novo or plain-error? II. Consistent with District of Colombia v. Heller, 554 U.S. 570 (2008), and United States v. Lopez, 514 U.S. 549 (1995), does Congress have authority to federally criminalize a wholly intrastate firearm sale and possession based only on the minimal showing that the firearms, at some point in time, traveled in interstate commerce? i