Whether 18 U.S.C. 16(b), as incorporated into the Immigration and Nationality Act’s provisions governing an alien’s removal from the United States, is unconstitutionally vague.That is a short question with deep ramifications. Dimaya is an immigration case, but the statute at issue, 18 USC § 16, is the general definition of "crime of violence" for the federal criminal code. Subsection (b) includes this definition: any felony that, by its nature, "involves a substantial risk that physical force against the person or property of another may be used in the course of committing the offense.”
For comparison, remember Johnson v. United States, a 2015 SCOTUS case that held a similar definitional phrase unconstitutionally vague: a felony that "otherwise involves conduct that presents a serious potential risk of physical injury to another.” Johnson's invalidation of this residual clause of the Armed Career Criminal Act triggered an earthquake in retroactive litigation. Of course, that was reduced to tremors with Beckles, which refused to find the (essentially) same phrase vague in context of the sentencing guidelines. A favorable decision in Dimaya may cause the ground to shift again, or at least clarify the Court's vagueness doctrine.
Dimaya might sound familiar. Last term, this same case was styled Lynch v. Dimaya (oh, how much changed with that name). It was first argued January 17, 2017, but then SCOTUS set it for reargument on October 2, presumably because the Court had deadlocked at 4-4. It appears that Justice Gorsuch will be the tiebreaker.