In 1956, Dwight Eisenhower broke Kentucky's nearly 30 year streak of voting Democratic in Presidential elections. Ike made large gains from his '52 showing in coal country and central KY. Ike's coattails flipped both senate seats, defeating majority whip Earle Clements.
Ike's surprisingly large win in KY was aided by Democratic infighting between new Governor Happy Chandler and Senator Earle Clements. Chandler contributed little to the party's efforts as his longtime rival, Clements, and a Clements ally were the two nominees for US Senate.
Longtime Rep. Bill Natcher saw his closest margin (by far) this year. His journals reveal his shock at the GOP wins and who he blamed. He writes that Ike's handling of the Suez crisis won over many newly enfranchised 18-20 year olds. Interestingly, he alleges mail ballot fraud.