It depends on what “great” is. FDR’s domestic policies were not great. His leadership skills in wartime were.
Exactly. Considering that FDR ushured us through the greatest economic crises in US history (the Great Depression)(even though badly...), AND the greatest war in world history (WWII), AND that he was in power for over 12 years.... one can call him the "greatest" (certainly the most influential) president of the 20th Century.
Of course in the "influential" sense, Hitler, Stalin, and Mao were "great" too.
Besides all that, FDR's biggest wartime leadership skill--was his military ignorance--and leaving the war up to the generals.
Blessedly, Marshall, MacArthur, Eisenhower, et al., were real pros.
Great means something different to a historian than everyone else.
Think of historical figures who have “the Great” appended to their names. They weren’t all rainbows and skittles, some of them were tyrants. “Great” in this definition means powerful, effective, not necessarily someone you agree with.
Do I know that’s what Newt meant? Not at all, but it’s possible.
BTW, Reagan praised FDR too, and he turned out OK.