MacArthur enjoyed periods of tremendous popularity amongst the American people only because he told them what they wanted to hear. During the darkest days of the first six months of WWII he boosted morale on the home front with his bold boastings and vainglorious self promotions. This popularity kept his head out of a figurative noose with FDR and forced the President to keep him in the limelight. The total debacle in the Philippines should have resulted in a Court Marshal; MacArthur's failure there was at least on the scale of Kimmel and Short's in Hawaii, and arguably greater.
While a certainly brave and capable officer at the unit level, at the strategic command level I believe him to be only marginally competent. He surrounded himself with incredibly loyal sycophants and apologists who, along with the active participation of Mac himself, covered up and glossed over his numerous mistakes and spun his image to the point of making him a military genius of the first order.
It was this image, cultivated at a time and in an environment which brooded little questioning, which would have potentially propelled him into a position as a running mate to Taft. However, 1952 was an entirely different time from 1942, Vice President is an entirely different position from Supreme Commander of Allied Powers, and politics is an order of magnitude different from the Army (ask Ike). He would have been subject to withering scutiny from the press and I believe that in short order his true image of a marginally competent, vainglorious publicity hound would have quickly surfaced.
I completely agree with the above post in that this TL is utterly dependent on him somehow being able to sidestep his sacking by President Truman in April, 1951. However, given his personality, I believe this to be virtual certainty.
Dave
www.pigboats.com