I guess if another war broke out in Europe, whether through anti-Bolshevism, or through an Anglo-Turkish clash, then keeping the USA out of it would seem a damn good move
Have Harding survive, perhaps run for a second term, and then surpress or prevent the Teapot Dome scandal. Then go from there. If we do have a more conservative "return to normalcy" then I could see him becoming like a 1920s Ronald Reagan, sans "tear down this wall" comment.