Ike was a lifelong Republican, although it was not widely known at the time. Truman himself even offered to step down and run as Eisenhower's VP in 1948 if he wanted. Ike turned him down because at the time he didn't want to get into politics.
There is some argument about that facts validity, but still an interesting idea.
In 1948 Senator Claude Pepper of Florida attempted to sway Democrats to support Eisenhower at the Convention in Philidalphia, but Ike said, "I do not want any office whether it be dogcather or Grand Hig Supreme King of the Universe!"