Really, given that he needed only 538 more votes in Florida, you could say that not holding one more rally in that state cost him the presidency.
It's sort of hard to fault him on Florida, though. It's the only state he outspent Bush in. He said it would come down to 1 vote per precinct (which actually turned out to be an overstatement), and he spent the final 33 campaigning nonstop in Florida.
The national and state polls all had Bush with a comfortable edge against Gore in late October 2000. Bush thought that with the election sown up he could campaign in California to pad his EV totals. That could have been a gigantic f-up had Gore won Florida. Rove would have looked like a complete idiot instead of the genius reputation he had.
