In Class v. United States, --- U.S. ---, No. 16-424 (2018), the question was whether a guilty plea by itself bars a
federal criminal defendant from challenging the constitutionality
of the statute of conviction on direct appeal.
The Court held it did not. Rather, because the issues raised "challenge the Government’s
power to criminalize Class’ (admitted) conduct" and "thereby call into question the Government’s power to 'constitutionally prosecute' him," Class could pursue those claims on appeal, despite his guilty plea.
It is important to note, however, the plea agreement in the case did not contain an express waiver of constitutional claims.
