"Bush won the majority of votes as cast..."

No he didn't - a majority means that most of the people who voted vote for you. What he at best might have got would have been a plurality - ie more votes than any other individual candidate.

To illustrate the difference - if you had ten candidates, and nine of them got 10,000 votes, and the other got 10,001 votes, that'd be the winner, with a plurality, and the votes of one in ten voters. Which is not "a majority."