Clarke Reed, a courtly Mississippi conservative who pushed his state’s Republican Party from irrelevance to dominance in the 1970s and helped lead the charge in turning the South from deep blue to ruby red, died on Sunday at his home in Greenville, Miss. He was 96.

The cause was complications of pneumonia, his family said in a statement.

Though his parents were both Democrats, Mr. Reed was a lifelong Republican. He got his first chance to vote in a presidential election in 1952, casting his ballot for the Republican candidate, the former Army general Dwight D. Eisenhower.

Mr. Eisenhower won the race in a landslide, but he still managed to lose the entire Deep South, Mississippi included.

That was no surprise: The Democrats — as the party of the Confederacy and, later, Jim Crow — had held a tight grip on the region since before the Civil War. In most Southern states, including Mississippi, the Republican Party was nothing more than a mailbox.

Mr. Reed set out to change that. Using his Greenville home as a meeting place and his business connections to open doors, he began recruiting candidates, organizing campaigns and pressuring powerful friends to switch parties.

Building the party was slow going, but Mr. Reed persevered. A licensed pilot, he thought nothing of hopping into his Piper Seneca six-seater for a quick flight to Jackson or Tupelo to meet with a potential candidate or a deep-pocketed supporter.