Why the Supreme Court ought to punt on Trump’s eligibility

Donald Trump’s Iowa caucuses romp raises the stakes in Trump v. Anderson, the Supreme Court’s review of a Colorado ruling disqualifying him from the state’s ballot. Soon after the justices hear the case next month, Trump could be the presumptive GOP nominee. The meaning of the 14th Amendment’s disqualification-for-insurrection clause will cease being an academic hypothetical and start being a question of whether states can, in effect, block an unfolding presidential nomination process.

Meanwhile, the Supreme Court briefs have poured in. Most retread familiar legal ground, but an amicus brief...