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The political party that controlled the American South for much of the 20th century was in many ways an authoritarian party. It blocked citizens from voting, prevented opposition parties from forming and sanctioned violence — including murder — to maintain its grip on power.

That party, of course, was the Democratic Party. And many of the same Southern politicians who oversaw a racial apartheid also voted with Franklin D. Roosevelt to create the modern American government — a government that helped build a new middle class through Social Security, union rights, financial regulation, antitrust enforcement and much more.

How could one party be both so reactionary and so progressive at the same time? That’s a story of historical circumstance too complicated to tell in a morning newsletter. But it’s worth remembering just how bizarre and unsustainable the party politics of mid-20th century America were. The Republican Party wasn’t cohesive either, home to both liberals like Thomas Dewey and conservatives like Robert Taft.