It is an argument that is effective in getting opponents of drug legalization to see an upside, though. The sort of person that tends to be in favor of prohibit

It is an argument that is effective in getting opponents of drug legalization to see an upside, though. The sort of person that tends to be in favor of prohibition and jailing of violators would likely respond to an appeal to the jailed with something along the lines of "well, then how would we keep those dangerous criminals off our streets?" There is very much a stigma among many baby boomers that drug users are violent, dangerous criminals who need to be locked away for their own good and ours (it's hilariously sad how many of my parents' friends casually equate pot usage with CSI-style psychopathic crackheads). The idea that they could be allowed to use without consequence is horrifying to them. However, "Yeah, this can fix your tax revenue problem" is a difficult upside to argue against; at that point, it's an argument of downsides vs upsides, rather than an argument about the virtue of taxing sales.