1. The idiot can't carry his own state (providing we think that Tennessee is still his own state).
2. The idiot is a former Senator. As we've seen recently with Dole, Kerry, and AlGore, time in the Senate is deadly for POTUS ambitions. Clinton should've noted that before she carpetbagged. The only modern Senator who has become POTUS is Kennedy, and that win came courtesy Cook County Corruption, Inc. As a rule, you can rule out all Senators when it comes to POTUS ambitions.
3. The problem with dissenting opposition party bombthrowers (and AlGore is certainly one of those) is that people will be constantly reminded of the outragous things they've said.