1992, 1988 or 1996?

Charlie Cook studies the endgame:

As things are going now, this election would appear to be on a track to match Bill Clinton's 1992 5.6 percent margin over President George H.W. Bush, the question is whether it gets to Bush's 1988 7.7 percent win over Michael Dukakis or Clinton's 8.5 percent win over Robert Dole in 1996. Maybe some cataclysmic event occurs in the next two weeks that changes the trajectory of this election, but to override these factors, it would have to be very, very big.