Eugene Talmadge or Olin Johnston runs third party, with Jimmie Davis or James Eastland as a running mate. SC, GA, FL, AL, MS, LA, as well as potentially VA, NC, and TX, vote for the Southern Democratic ticket.
287: Thomas Dewey/Theodore Roosevelt, Jr. or Wendell Willkie - 49.4%
161: Henry Wallace/Estes Kefauver - 44.0%
83: Eugene Talmadge/James Eastland - 5.3%
Others - 1.3%
If the ticket was Happy Chandler/Strom Thurmond, I can see them getting national ballot access, winning TN, AR, TX, and KY, and getting Wallace to lose the West.
Dewey appoints a Cabinet that mixes internationalists, new Taft conservatives, new Dewey liberals, and Hoover Old Guard members.