Plea deal did not waive Habeas challenge to sentence, so long as the Habeas minimum showing is met, as parties can't stipulate to a sentence in excess of legal limits.
So long as there is a valid petition arising from a Supreme Court holding made retroactive to cases on collateral review, non-retroactive cases decided in the interval can cited to describe the current state of the law.
Under categorical review, state robbery statute isn't a valid predicate; petitioner did not brief whether state burglary statute is covered under the elements clause of the law; challenge to that predicate conviction is therefore waived.