President Bloomberg?

As Michael Bloomberg is the first to admit, he's a divorced, Jewish billionaire from New York and that, in and of itself, could be a tough sell as president. Still, it looks like Hizzoner is positioning himself to run for president with yesterday's announcement that he's leaving the Republican party. (Talk about flip flopping.) . When you've got more than $5 billion to his name, why not? It makes Mitt Romney's quarter-billion dollar fortune look like chump change and people are clearly dissatisfied with politics in general and both parties in particular.

It's hard to see, though, how a third-party candidate even a very rich one can be anything more than a spoiler without a fundamental shift in the physics of American politics. It's legendarily hard to get on the ballot around the country but assuming you can surmount that the history of third-party movements shows how hard it is to win. The very strong third-party candidacies of the 20th century--Teddy Roosevelt in 1912; Henry Wallace and Strom Thurmond in 1948; George Wallace in 1968; Ross Perot in 1992--have all been about defections from one of the major parties. Teddy Roosevelt's Bull Moose was about Republican progressives being alienated from President Taft. Wallace saw the defection of segregationists and populists from the Democrats; Perot drew from disappointment in the first president Bush. All were spoilers. Only Wallace got electoral votes and that was because of his strength in the South.

It's a truism of American politics that only if a third party can draw from both parties in substantial numbers could they really have a shot. At the moment, it's hard to see either party nominating such a polarizing figure that Americans turn their lonely eyes to Bloomberg. Yes, Bloomberg can win in a Kucinich-Tancredo race. Does a Clinton-Romney race really leave that much running room in the middle? Obama-Giuliani? What if it's already a subway series of Clinton versus Giuliani? There's a market place for something out there but I suspect it's more for an anti-trade-and-immigration populist than a free-trade Wall Streeter like Bloomberg who offers the spinach of entitlement cuts.

Besides, are anti-trans-fats and smoking really the best platform for carring middle America? Politicians who seem to transcend ideology get fawning treatment from the media. See this week's TIME cover story on Arnold Schwarzenegger and Bloomberg. But in the maw of a national campaign they may find themselves like John Anderson of 1980. If ever there was a time for a centrist candidate to triumph, it should have been 1980 when the moderate Republican congressman from Illinois bolted the GOP to form a National Unity Party after failing in his bid to win the Republican presidential nomination. Jimmy Carter's support had collapsed. Ronald Reagan, the Republican nominee, was considered a polarizing figure. John Anderson promised to govern sensibly and, like, Bloomberg talked about tough choices and honest. (He campaigned on a 50 cent gas tax among other things at a time when gas was about $1 a gallon.) He started out at 25% in the polls and sank to 7% by election day. He got no electoral votes. Granted, Bloomberg has $5 billion, but he is still a divorced Jewish billionaire from New York.