As an aside, the author of the study clerked for a Reagan appointee (who was also a Hoover Institute fellow), is from an especially conservative law school, and seems to have published so far almost exclusively on this particular topic.
I would personally want to do more research on this person and his writings before taking his entire argument at face value.
It's interesting to see such a true example of the ad hominem fallacy.
You can very easily do more research on his writing on mass incarceration, since he appears to be internationally famous for it, is cited widely, and writes on the Internet about it.
Worth the reminder: I find no evidence that the author thinks that the drug was is a good thing, and lots of evidence that he sees mass incarceration as a problem.
In fact, if you want to do more research on the paper, you could start by reading it: the author doesn't even think most violent offenders should be incarcerated.
His arguments are laid out in detail. His data is available for inspection. Could you explain the relevance of his conservative bonafides? If he were a more typical liberal professor, would that also be relevant?
What I see the author doing as I read his work is finding a lot of ways to use different definitions of terms to determine which offenders count as "drug offenders". His assumptions are notably different from the assumptions of some other researchers. It seems possible to me, at least on first skimming of these articles, that a lot of the differences in the data that Pfaff uses can be accounted for by these alternative definitions of terms.
For instance, I grant that a "violent offender" who is in jail on a principal charge of shooting a police officer while in the process of being arrested on a drug charge or during a drug raid was indeed violent, and is rightly viewed differently than a "non-violent drug offender".
But we still have to acknowledge that if there were no War On Drugs, then there wouldn't be as many of those drug raids and drug arrests to begin with. The circumstances for many of those violent crimes simply would not occur.
So, the process by which you sort the offenders into batches seems to have a strong impact on the conclusions you make.
Between selecting your data sources, methodology, hypothesis, outlier treatment, and even the choice of publishing or not your findings there is so much room for bias that the author identity can not be ignored.
Now, if other people go do different research on the same hypothesis, and still get the same result, and those people do publish everything they have, then you'll have an objective body of work you can just inspect and trust that it's real.
I did not attack the person, but I questioned modern science and particularly statistics as such. But it is much easier to believe what you read than to think for yourself.
I would personally want to do more research on this person and his writings before taking his entire argument at face value.