In Lester v. United States (Apr. 29, 2019), the full court declined to rehear en banc whether Johnson retroactivley applies to the mandatory pre-Booker residual clause in the Guidelines.
Writing for himself, Judge William Pryor authored a lengthy opinion explaining why any ruling extending Johnson to the Guidelines would not be a substantive rule, and therefore would not have retroactive effect in cases on collateral review. He emphasized that, unlike in the ACCA context, the defendant's sentence would remain within the statutory ranges authorized by Congress, and he could receive the same sentence today. He also reasoned, in a lengthy discussion, that judicial decisions don't actually change the law but rather recognize what the law has always been.
Judge Martin, joined by Judges Rosenbaum and Jill Pryor, opined that the Eleventh Circuit's decision in In re Griffin was wrong, both that Johnson did not apply to the mandatory Guidelines and that any such ruling would not be retroactive.
Judge Rosenbaum, joined by Judges Martin and Jill Pryor, wrote separately in response to Judge Pryor's more theoretical comments that the Guidelines were never mandatory at all, and that judicial opinions don't actually change what the law always has been. "He reasons that since the Supreme Court in Booker found that the mandatory Guidelines violated the Sixth Amendment, they 'were never really mandatory,' even though courts applied them that way for two decades. Hmm. I doubt the perhaps 1,000-plus inmates who sit in prison right now because a court sentenced them using a mandatory version of the Guidelines with an indisputably unconstitutionally vague career-offender clause would agree. . . . Under Pryor's reasoning, the Guidelines were never mandatory, but to inmates like Lester, they will always be mandatory, since these prisoners remain subject to their punishment. This heads-I-win-tails-you-lose logic cannot withstand scrutiny."