Because some intelligence revealed toward the end of his presidency that the US might be falling behind in weapons technology--the famed (and untrue, actually the US was far ahead...) 'missile gap. read more
In 1952, leading Republicans convinced Eisenhower (then in command of NATO forces in Europe) to run for president; he won a convincing victory over Democrat Adlai Stevenson and would serve two terms in the White House (1953-1961). read more