SCOTUS decides that once a federal prisoner has challenged his sentencing post-conviction once, that’s it. Even if another court rules differently, on an identical-ish case, if there is no new evidence for his particular case or statutory change in the law — he cannot contest the crime further due to a technical interpretation of federal law.
TL;DR: even if you are innocent, SCOTUS says you can’t contend your federal incarceration more than once.
