How many federal prisoners may have Dimaya claims and how many procedural challenges will they face raising them?

The big Supreme Court vagueness ruling in Sessions v. Dimaya, No. 15-1498 (S. Ct. April 17, 2018) (available here), is properly being discussed as a significant immigration ruling: the Justice were considering (and struck down as vague) how Congress defined an offense of violence in 18 U.S.C. § 16(b) in a case involving a alien subject to deportation for committing a certain kind of crime.

But, critically, the now-unconstitutional definition of a "crime of violence" in § 16(b) is referenced throughout the federal criminal code within various criminal offenses and sentence enhancements.  And, notably, definitional language identical to § 16(b) appears in 18 U.S.C. § 924(c)(3)(B), which is part of a statute that adds significant amounts of prison time for any possession or use of a gun in connection with a crime of violence.  In other words, as the title of this post suggests, there are certainly some number of persons serving federal prison time based on a definition of a  "crime of violence" deemed unconstitutionally vague in Dimaya.

But, as my post title suggests, it is hard to know how many federal prisoners have viable Dimaya claims, while it is easy to know that all prisoners will face an array of possible procedural headaches when trying now to raise Dimaya claims.  Helpfully, Leah Litman thoroughly covers, in this lengthy new Harvard Law Review blog posting, the array of procedural hurdles that Dimaya defendants are likely to face.  Here is how her extended piece starts and ends:

The Supreme Court decided Sessions v. Dimaya and struck down the federal definition of “crime of violence” as unconstitutionally vague. The statute, section 16(b) (along with its very analogous cousin, section 924(c)), has meaningfully contributed to mass incarceration, racial disparities in sentencing, and excessive sentencing at the federal level. Dimaya recognized that section 16(b) did so in part through sprawling, amorphous phrasing that could be interpreted and applied in capricious and largely unbounded ways to expand the category of “crime of violence.”  The impact of the Dimaya decision is potentially enormous, both for deportations (the case before the Court) and for criminal sentences....

Whether Dimaya rights wrongful convictions will depend on how courts interpret a slew of procedural restrictions on federal resentencing and federal post-conviction review....

Dimaya spoke of “lesson[s] so hard learned” from Johnson and the ACCA debacle that Johnson corrected.  But another lesson that was hard learned from Johnson is that Johnson, or in this case Dimaya, will just be the beginning.  Whether those decisions will ultimately benefit the individuals who are currently wrongly incarcerated will depend on what comes next, and specifically on how courts interpret the many draconian restrictions on post-conviction review.