Biden knows the mercurial polls now tell him that he must re-emerge and cease being a virtual candidate. Yet he knows that if he does, he risks losing the race. So his surrogates talk of mandatory fact-checking of the debates -- or even canceling them entirely.

Hillary Clinton recently said that Biden "should not concede under any circumstances," apparently even if he loses the November election. If the rules no longer favor Biden, then it seems time to change the rules.

So Biden has become a tragic prisoner of his own paradoxes.