I think there's a more plausible storyline for Garner becoming President.
From Wikipedia:
In February 1933, an assassin, Giuseppe Zangara, fired five shots at Roosevelt, missing him but killing the Chicago Mayor Anton Cermak.
Roosevelt is shot at in Miami as President-elect, he dies, and Garner is inaugurated President.
That timeline has been done many times before and it always turns out that everything goes to hell because Roosevelt wasn't there to protect us, which I think is a bunch of bullsh**t but whatever. This is more interesting because this scenario focuses more on Garner's handling of WWII and the aftermath then on his dealing with the Great Depression.
Garner was no Roosevelt. He wouldn't have run for a third term probably.
