Why would Lindbergh be running for President? How senior was he in the anti-intervention movement (which was allied to the GOP due to its hostility towards the Democratic FDR)? I thought he was sort of a more-erudite-than-usual celebrity spokesman for America First.
I think if FDR is going to be beaten by anyone in the anti-war movement, it'd probably be Taft...he nearly got the 1940 GOP nomination, but was edged out in a quasi-coup by Wilkie's supporters. Of course, Lindbergh, being a celebrity, could be incorporated into the government somehow.