OF course, FDR had a third and fourth election where his totals fell off a bit from his second term totals.
One more observation...
Presidents seeking re-election who LOST, but still got more popular votes than they did in their first term:
Grover Cleveland, 1888
Martin Van Buren, 1840
The Protestants went back to voting Republican after they messed up in 1932 and 1936.