We have heard much about the puzzle that US economic performance under President Joe Biden has been much stronger than voters perceive it to be.  But the current episode is just one instance of a bigger historical puzzle:  the US economy has since World War II consistently done better under Democratic presidents than under Republican presidents.  This fact is even less widely known, including among Democratic voters, than the truth about Biden’s term.  Indeed, some poll results suggest that more Americans believe the reverse, that Republican presidents are better stewards of the economy than Democrats.