Williams is evidently not aware of two top UCLA Economists, (not exactly a bastion of Convervativism), whose research recently credited Roosevelt with extending the Depression by 6 or 7 years by implementing exactly the wrong Economic policies from what was needed.
Of course we couldn't expect the Mainstream to research anything they write - could we.
Also, FDR fooled Ronald Reagan four times too, and five if one counts the Truman “fifth” term for FDR.