The GOP’s push to repeal the Affordable Care Act is running out of steam—and time. Unless Republicans can agree by Sept. 30, they won’t be able to pass a bill without 60 Senate votes. So here’s a wild idea: Instead of repealing ObamaCare, make it unconstitutional.

Recall how the Supreme Court split when it upheld ObamaCare in 2012. Four justices thought the law’s individual mandate—the requirement that Americans buy health insurance or pay a penalty—was unconstitutional. Another four thought it was hunky dory. What broke the...