The Blue-State Exodus Could Have Profound Effects on GOP Power

Americans' interstate-migration trends since the pandemic might foretell a new demographic destiny.

Conservatives have noticed approvingly that deep-blue states such as California and New York have been losing residents to deep-red ones such as Texas and Florida since the pandemic. Many note that this points to the comparative advantage low-tax places have in attracting businesses and families. Few have noted, however, the possibly profound positive effect this migration — if it continues — will have on the Republican Party’s chances to win power.

The Brennan Center for Justice, a liberal nonprofit, recently projected that states...