Michael Bloomberg could run a solid centrist campaign and be the only candidate from New York. He would be more sane and stable and just as well financed as Ross Perot. Ross Perot won 19% of the vote but nothing in the electoral college.
One interesting scenario is if Bloomberg captures New York (31 electoral college votes) and say another big state or two (with a solid vice presidential selection and generally solid campaigning). He ends up with 60-150 electoral college votes and neither Obama or the Republican nominee gets a majority. I think for Michael Bloomberg to win the Republican party would need to continue to collapse in public opinion and the Democratic candidate would need to be out campaigned by Bloomberg.
The electoral college apportionment rules for a minority vote kick in.
A candidate must receive a majority of votes from the electoral college (currently 270) to win the Presidency. If in either election for President or Vice-President no one receives a majority, the election is determined by Congress (the House votes for presidential candidates, and the Senate votes for vice presidential candidates).
The Democrats would probably retain their control of the House and Senate, which would seem to give a democratic president in the event of any minority electoral college result in 2008.
If Bloomberg and the Republican and Democrat candidates all had minority electoral college numbers but Bloomberg had the most electoral college numbes and the Democrat second and the Republican third, then would Democrat controlled House and Senates vote for a more popular Bloomberg if that were the majority minority will of the people ? Something like 40% Bloomberg, 35% Democrat and 25% Republican in terms of electoral college numbers.
The Republicans running for president are very weak in terms of popularity.
Presidential prediction markets are fairly accurate predictors of election results
Candidate Party Price Change
Barack Obama D 39.90 +3.400
Hillary Clinton D 23.00 -4.000
John McCain R 14.50 +1.200
Rudy Giuliani R 11.40 +0.200
Mike Huckabee R 4.60 +0.000
Mitt Romney R 4.50 +0.300
Ron Paul R 2.30 +0.500
Michael Bloomberg R 1.70 -0.300
So it is 2 to 1 in favor of a Democrat winning and Obama and McCain are currently the favored candidates in the betting.
Both Ron Paul and Michael Bloomberg could go outside the normal nomination process and split up the normal two party action.
The Wall Street Journal believes that the threat of a Bloomberg campaign could force the Democrats and Republicans toward more centrist positions
Newsday considers the wildcard of a Michael Bloomberg candidacy
Bloomberg's chances likely would hinge on a difficult strategy in which he wins the more liberal Northeastern and West Coast states rich with electoral votes, plus some moderate Midwestern states such as Ohio. But even then he would fall short of 270 electoral votes, said Jason Gimpel, a government professor at the University of Maryland.