1. May a defendant, faced with a silent record below, prove that his ACCA enhanced sentence was in deed based upon the residual clause through a process of elimination? And in doing so, can he rely on post-sentencing case law, including this Court's decisions cla rifying the other ACCA clauses ?

2. Is USSG § 4B1.2(a)(2) 's residual clause void for vagueness with respect to defendants sentenced under the pre -Booker mandatory Guidelines ?

Whether a defendant can prove his ACCA-enhanced sentence was based on the residual clause through a process of elimination and rely on post-sentencing case law