In the fifty years that followed the war, the Democratic Party nearly always won all the states that had been part of the Confederacy. The “Solid South” shows up on electoral maps from those years. During the four-term presidency of Franklin D. Roosevelt, some of the Southern states began to defect from the Democratic fold, but it was not until the Civil Rights struggle of the mid-1960s that the switch became permanent. When he signed the Civil Rights Act of 1964, President Lyndon B. Johnson was reported to have said, “There goes the South.” If so, he was right. Ever since the late 1960s, the South has been solidly Republican, with a few small countertrends.

That the South tends to vote as a bloc gives it political power, and no politician, Republican or Democratic, can ignore its importance. By contrast, the North, the Midwest, and the Far West have alternated, sometimes favoring one party or the other.