The House-led federal government shutdown is more than maddening, but nobody should be surprised by the Republican confederacy behind it. Nor should anyone underestimate this century’s secessionists.

This fight has been seeping inward from the political margins for years, where increasingly ideological Republicans—from Tea Partiers in Congress, to red-state governors, to Chief Justice John Roberts—seek a less perfect union.

They are not the political stepchildren of Ronald Reagan, who, after his day’s political battles, shared a belief in a functioning federal government with his top adversary, Democratic House Speaker Tip O’Neill. They are closer to the GOP activists drawn to Barry Goldwater’s 1960s-era Conscience of A Conservativemanifesto, which counseled killing government and not making it work.

The most apt historical precedent for today’s marauder Republicans is the old Confederacy, where the provocateurs are not merely intent on stopping federal governance, but withdrawing from it or sabotaging it if they can’t get their way. Today’s Tea Party darlings like Texas Sen. Ted Cruz and the House right-wingers driving the federal shutdown are cut from the same disunionist cloth as the old Southerners who fomented secession and the Civil War....