Who Really Qualifies as the "Worst President Ever"?

In his victory speech after the Iowa Caucuses, Donald Trump described Joe Biden, his likely opponent in November’s election, as “the worst president in the history of our country… There’s never been anybody like him.”

Though it’s easy enough for loyal Democrats to dismiss this judgment as one more example of typical Trumpian over-statement, this latest, high-profile insult does raise an important and disturbing question.

Each of our last four chief executives—George W. Bush, Barack Obama, Donald Trump and Joe Biden—has been characterized by the angry voices of partisan critics as “the worst president ever.” Could it possibly be true that over the last quarter century, our long-suffering Republic has been afflicted by such an appalling and unprecedented cavalcade of losers?

And if so, does this extended ordeal of incompetent and misguided leadership help to explain the corresponding opinion polls that show a long-standing public tendency to judge the nation as headed in the wrong direction?