What legally distinguishes a "non-violent Federal cannabis offense" from a violent one (and would multiple SCOTUS rulings be needed to sort this out)?

The question in the title of this post is prompted by key language in the resentencing and expungement provision of the "discussion draft" of Senate Majority Leader Chuck Schumer's new federal marijuana reform bill, the Cannabis Administration and Opportunity Act.  The full text of this CAO "discussion draft" is available here; this highly-anticipated bill draft runs 163 pages and covers all sorts of reform and regulatory issues related of federal marijuana law and policy (see coverage here at MLP&R).  Of course, I am distinctly interested in the criminal justice provisions of this bill, and I was excited to see there is a dedicated section (sec. 311) devoted to "RESENTENCING AND EXPUNGEMENT."  But the CAOA bill draft includes a notable (and I think problematic) linguistic limit on the reach of resentencing and expungement.

Specifically, the main expungement provision of the CAOA calls for automatic expungement of only a "non-violent Federal cannabis offense."  CAO sec. 311(a)(1) (emphasis added).  Similarly, the provision allowing for "sentencing review" states:

For any individual who is under a criminal justice sentence for a non-violent Federal cannabis offense, the court that imposed the sentence shall, on motion of the individual, the Director of the Bureau of Prisons, the attorney for the Government, or the court, conduct a sentencing review hearing.  If the individual is indigent, counsel shall be appointed to represent the individual in any sentencing review proceedings under this subsection.

CAO sec. 311(b)(1) (emphasis added).  I really like the provision requiring the appointment of counsel for these "sentencing review proceedings."  But I wonder and worry that, if this provision were to become law, counsel might be spending way too much time just figuring out whether prospective clients qualify as "non-violent" federal cannabis offenders. 

Though we all often use terms like violent and non-violent as offense descriptors, federal criminal justice practitioners know all too well that there is never-ending litigation in the context of many other federal statutes and provisions concerning whether certain prior offenses qualify as "violent" or not.  (Frustrated by just one small piece of this litigation, I joked in this post that one of the circles of hell set forth in Dante's Inferno surely involved trying to figure out what kinds of past offenses can or cannot be properly labeled "violent.")

Especially troublesome in this context is the realty that, technically, all basic federal drug offenses are "non-violent" because there are not any formal elements of these offenses that require any proof of force or injury.  And yet, more than a few "drug warriors" have been heard to say that all drug crimes are by their very nature violent and that the only types of  drug offenders who get the attention of federal prosecutors are those who have a violent history or violent tendencies.  Consequently, I would expect that federal defense attorneys would have a basis to argue that every  "Federal cannabis offense" qualifies as non-violent, while federal prosecutors would likely contend that at least some (many?) federal cannabis offenders are to be excluded by this "non-violent" limit in the bill text.

I suspect that this section of the Cannabis Administration and Opportunity Act was just drawn from similar language in the House version of proposed federal marijuana reform (section 10 of the MORE Act), and the CAOA's current status as a "discussion draft" should provide an opportunity to clean up this problematic adjective.  Though I understand the political reason for wanting to distinguish less and more serious drug offenders for expungement and resentencing provisions, the "non-violent" terminology seems to me quite legally problematic.  (There are other aspects of the "RESENTENCING AND EXPUNGEMENT" section of this new bill that are far from ideal, but this terminology struck me as the biggest red flag.)

Some related work in this space:

• "Marijuana legalization and expungement in early 2021" 
• "Ensuring Marijuana Reform Is Effective Criminal Justice Reform"
• "Leveraging Marijuana Reform to Enhance Expungement Practices"

A few of many prior recent related posts:

• "Merrick Garland, cannabis policy, and restorative justice"
• Congressional Budget Office estimates bill to end federal marijuana prohibition would reduce federal prison time "by 73,000 person-years, among existing and future inmates" 
• Noticing marijuana reform as criminal justice reform in Arizona after passage of Prop 207
• Terrific coverage at CCRC as "Marijuana expungement accelerates across the country"