What if General McArthur rides the discontent over his firing and over the Korean war to the White House in 1952? I think He would be much more conservative than Eisenhower and leave situations like the Suez crisis alone.
For MacArthur to have any chance whatever of getting the GOP nomination, Taft has to be dead by 1952. Otherwise he will simply divide the Right and make it easier for Eisenhower to win the nomination than in OTL.
But even if Taft is gone and the race for the GOP nomination is a pure Ike-MacArthur one, Ike wins. By 1952, the hysteria surrounding MacArthur's firing had largely died down, and Eisenhower represents the sort of military man the American people have generally preferred--the non-threatening type (like Grant saying "let us have peace" in 1868 or the Colin Powell boom in 1996) as against the type that can be seen as a "man on horseback" (Leonard Wood, Curtis Le May, Alexander Haig etc.) And state GOP officials, who were divided between Ike and Taft in OTL, would be more heavily pro-Ike in this ATL, fearing MacArthur as a megalomaniac and a loose cannon.
Sure, millions of Americans looked on MacArthur as a hero. But millions looked on him as a hero in 1948, too, and the campaign for him went nowhere that year; indeed, it showed how inept he was at civilian politics. And in 1952, of course, MacArthur would be four years older--he would be 72, three years older than Reagan was in 1980.