1932: John Nance Garner vs Herbert Hoover

[Southern Senator North Carolina Yankee]

By 1936 the US was still Deep in the Depression granted it had improved slightly(Unemployment going from 25% to 15 or 16%) but it was still a Depression and without the Charismatic FDR it is possible that Landon or maybe someone else could have beaten Garner in 1936. It is also possible that Garner could have lost the nomination to someone on the left.
The Depression was a monster and it could have eaten any politican for Breakfast and spit them out for lunch. Indeed that almost happened to FDR in 1940. Had that election been about the economy then Wilkie would have won. The economic gains that FDR had achieved were lost in 1937-38, Plus Roosevelts attempt to pack the Court, and breaking the three term precendent together would have been enough to send him packing. With the growing threat of Hitler and the Japanese Americans though it seemed best to stick with a strong leader then to choose an unknown in uncertain times.