While this doesn't directly answer your question, you may be interested in this previous answer I gave in this sub here about the passage of the 22nd Amendment that enacted term limits for U.S. Presidents. TL;DR: Several Presidents had tried, but failed, to run for a third term before FDR, while the idea of there being an official, legal Constitutional Amendment enacting term limits for Presidents dated back to Andrew Jackson's advocacy for such an amendment. There was criticism of FDR for doing it, just as there had been criticism of other presidents for attempting it but failing. The 22nd Amendment gained much of its political popularity precisely because FDR had finally broken through as the first three-term (and four-term) president.