Pexton Hall is a heavily secured building at the treatment facility in St. Peter where some of those who have been civilly committed to the Minnesota Sex Offender Program (MSOP) are held. (The Minnesota Star Tribune)

A federal appeals court this week gave a dubious legal pass to Minnesota's controversial sex offender civil commitment program. But this does not give Gov. Mark Dayton and state lawmakers an excuse to step back from reforming an increasingly costly, taxpayer-funded program that locks people up long after they've served jail time for their offenses.

The panel decision from the Eighth Circuit Court of Appeals came on Tuesday. It reverses a courageous 2015 lower court ruling by U.S. Judge Donovan Frank declaring the Minnesota Sex Offender Program (MSOP) to be unconstitutional. The appellate court decision indefinitely halts the modest reforms ordered by Frank. It also regrettably makes it more difficult politically for state policymakers to tackle changes needed to rein in the program's soaring costs (currently $83.7 million a year) and modernize program practices, as other states have done.

To be clear, reform does not mean throwing open the doors at prison-like facilities in Moose Lake and St. Peter. Instead, it involves developing a clearer, more consistent system to evaluate offenders' ongoing risk after years, even decades, of treatment. It also includes establishing less restrictive and less expensive housing facilities for those deemed less likely to re-offend — such as the elderly. The oldest person held in the program is 85.

Right now, the 23-year-old state program, supposedly a "treatment program," essentially imprisons people for the remainder of their lives. Just one person has been fully discharged, a data point that makes the program an outlier even among states with similar civil commitment programs. It also is the key point driving constitutionality concerns about the program. Providing treatment is allowable, according to courts, but not simply locking people up for good after they've served their sentences.

Minnesota politicians' fear of being labeled "soft on crime" has made changes nearly untouchable. The Frank ruling provided the political cover necessary to move forward; neither party could blame the other for changes ordered by the court. The Eighth Circuit's decision, which came because Dayton's administration appealed Frank's ruling, removes this shield.

Reforms are still critical, something that has been made clear by a bipartisan task force and a 2011 report from the respected Office of the Legislative Auditor. Lawmakers should press on, but neither party's leaders are likely to touch it with a gubernatorial race looming next year. At this point, the best hope is that the state judiciary will shoulder the responsibility of demanding a much more well-defined set of criteria for committing offenders and ensuring that adequate ongoing risk assessment is taking place. Dayton's administration should also continue the small steps it has taken to update program practices.

We will let others dissect the legal reasoning of the Eighth Circuit Court's ruling, as Harvard Law Prof. Noah Feldman did in a critical commentary appearing on these pages Friday. The point we choose to emphasize is that the end result of the appellate court's decision is this: If the state decides someone is dangerous, it has sweeping powers to lock that person up forever.

This chilling legal principle could one day threaten liberties far beyond those of the 721 people in the Minnesota sex offender program. That should provide ample reason for the U.S. Supreme Court to hear this case if and when it is appealed.