The only thing I can think of is Bill Clinton getting assassinated on November 1st or 2nd. To pull 1/3 of the popular vote, and win only Arkansas and DC? Not going to happen if Clinton's still alive, or gets killed early enough for the Democrats to substitute.
Even then, I still don't think 1/3 of the country votes for the late Gov. Clinton, since they'd be concerned about what'd happen to their vote, and then I have no idea how to get that Bush/Perot split out of this.
This probably requires some serious ASB stuff.