No one opposes ObamaCare more than we do, and Democrats are now confirming that it was designed as a way-station to government-run health care. But a federal judge’s ruling Friday that the law is unconstitutional is likely to be overturned on appeal and may boomerang politically on Republicans.

Judge Reed O’Connor ruled for some 20 state plaintiffs that the Affordable Care Act’s individual mandate is no longer legal because Republicans repealed its financial penalty as part of the 2017 tax reform. Recall that Chief Justice...