Those of us who believe the war on drugs has been a failure — even a fiasco — shouldn’t have to invent or exaggerate reasons for idling it down. There is more than enough evidence for the debacle without clinging to myths.

Unfortunately, last week District Attorney Mitch Morrissey was labeled a “snake” and a “villain” by a fellow Denver Democrat, Sen. Pat Steadman, for merely pointing out that a central premise of those who would reduce penalties for possessing certain drugs in Colorado is false.

Morrissey insists our prisons are not bulging with felons who’ve done nothing more than indulge in personal drug use.

This common claim by sentencing reform advocates is, he insists, misleading in the extreme.

Morrissey appears to be right. Colorado prisons house more than 20,000 inmates, and yet Denver — ground zero for the state’s most destructive drug subculture — sent just 21 people to prison last year for the felony of possessing such drugs such as methamphetamine or ketamine. Significantly, not one was someone who screwed up just once, twice, or even three times.

Not one was simply a recreational drug user who happened to stumble into the arms of police — or, to cite the common stereotype, was ensconced in the privacy of his home when rousted from a drug-induced reverie by jackbooted cops.

Every single offender had a lengthy, sometimes staggering, history of run-ins with the law. Several were incarcerated for other crimes, too.

One fellow convicted for possessing meth had served a number of years for attempted murder. Several had prior sentences for assault or burglary. Some had served time in other states.

To be sure, a large percentage of their arrests — and in three cases, the arrests date back to the 1970s — probably were in some sense related to drugs. That was clearly true of the only woman on the list, whose drug or alcohol-related incidents span a dozen years.

But the flip side of that probability is the likelihood that some or many of them had been through drug treatment before, too, without discernible result.

The dustup between Morrissey and Steadman occurred over Senate Bill 163, which originally sought to reduce a number of drug offenses from a felony to a misdemeanor. The bill has since been amended, under pressure from district attorneys, to authorize a study of sentencing guidelines for drug offenses. In other words, it’s been gutted; hence Steadman’s ire.

Republican Sen. Shawn Mitchell, a co-sponsor of SB 163, is correct when he says we should be counseling and treating drug addicts rather than throwing them in prison. But as a general rule, that’s already what we do with all but the incorrigible who can’t stay out of other trouble — as Mitchell mostly conceded recently when we spoke.

Where Mitchell most disagrees with Morrissey is on whether prosecutors need the hammer of a possible felony conviction to force repeat offenders into treatment — or to take treatment seriously. Mitchell counters that misdemeanor penalties — especially for repeat offenders — are hardly trivial, and that a felony record needlessly sabotages future prospects.

“This is not legalization or decriminalization,” he emphasized. Nor would it affect drug dealing.

Mitchell speaks with the experience of a brother with a drug addiction — “what is our interest in putting him behind bars?” — and I share his conviction, as he said during a recent TV interview, that “we’re not winning the war on drugs … . We’re making government more powerful and police departments well armed but we’re not solving the drug problem.”

Still, Colorado’s prosecutors and drug courts already do appear to prefer treatment before incarceration in the vast majority of cases. So even if there’s room for additional sentencing reform, we should at least acknowledge that it’s not going to empty our prisons, and that prosecutors aren’t snakes for merely pointing that out.

E-mail Vincent Carroll at vcarroll@denverpost.com. Follow him on Twitter @vcarrollDP.