Texas Gov. Greg Abbott’s defiant statement on Wednesday rejecting the federal government’s authority to enforce immigration law at the U.S.-Mexico border ratcheted up the already tense stand-off between the state and the Biden administration — and signaled how fully the GOP has become the party of the Southern conservatives it was founded to fight.

Abbott’s declaration that the Biden administration had “broken the compact between the United States and the States” by failing to “fulfill the duties” of protecting Texas from an “invasion” is an eerie echo of the political thought that gave rise to nullification and secession in the 19th century and resistance to desegregation in the 20th.

Prior to the Civil War, the prevailing view among Southern elites was that the Constitution of the United States of America was merely a compact between the states. Under […]