After 16 straight years of Democratic administrations, I see no reason why the successful and high profile Governor of California, with the war hero MacArthur by his side, would not handily defeat the rather obscure Senator from Illinois and the well respected, though segregationist, Senator from Georgia.
Warren would very likely sweep the plains, mountain, southwest, and western states, as well as realize a huge success in the northeast and the midwest.
The Democrats would continue to have a stranglehold on the south.
Warren/MacArthur 301
Lucas/Russell 230