The candidate you are thinking of is Robert A. Taft, Senator from Ohio and eldest son of William Howard Taft, the 27th President of the United States, which could be candidate for 1948, if Thomas Dewey is unable to.
Dwight D. Eisenhower as 16th Chief of Staff of the Army, was in 1945 told by Harry S. Truman during the
Potsdam Conference that if Eisenhower desired, the president would help the general win the 1948 election, and in 1947 he offered to run as Eisenhower's running mate on the Democratic ticket if MacArthur won the Republican nomination.
So its not ASB and a Eisenhower/Truman ticket, could hold 1948, while an alternative running mate, such as in 1952, could be interesting, such as Senator Hubert Humphrey from Minnesota, Senator Estes Kefauver from Tennessee or Senator Robert S. Kerr from Oklahoma.