Bloomberg Presidential Buzz Grows

With an increasingly cacophonous buzz that he's contemplating an independent run for president despite public pleas to the contrary, New York Mayor Michael Bloomberg took a clear step toward that third-party bid on Tuesday by changing his party registration from Republican to "unaffiliated."

"I believe this brings my affiliation into alignment with how I have led and will continue to lead our City," Bloomberg said in a statement, referring to how the one-time Democrat famously changed his party registration once before to run for mayor as a Republican. "A nonpartisan approach has worked wonders in New York: we've balanced budgets, grown our economy, improved public health, reformed the school system and made the nation's safest city even safer."

A Bloomberg aide tells ABC News there is a four-part test for the mayor to decide whether or not he'll get into the race after the Democratic and Republican presidential nominees are chosen next spring.

First, both party's nominees need to have unfavorable ratings at least in the 40s. Second, 70 percent of the nation needs to think the country is headed in the wrong direction, as is the case currently. We're there right now. Third, at least 60 percent of those polled need to have their minds open to a possible third-party bid. Lastly, 20 percent to 25 percent need to be open to the notion of President Mike Bloomberg. If those four criteria are met, Bloomberg will throw his hat into the ring.

ABC News' chief political correspondent George Stephanopoulos says Bloomberg's announcement taps into voters' frustrations.

"You now have a national figure giving voice to the national mood," Stephanopoulos said. "Americans are fed up with Washington. President Bush is near a record low in approval ratings. The Democratic Congress is near a record low in approval ratings. More Americans call themselves independent. He's seeing if he can create a movement out of this mood."

Bloomberg's Big Buddy in California

Bloomberg's party switch came just hours after a swing through California where Bloomberg bashed Washington, D.C., as "sinking into a swamp of dysfunction", and at a conference entitled "Cease-fire! Bridging the Partisan Divide" called for a new type of non-partisan leader.

"The point of this conference is clear," Bloomberg said Monday evening. "We do not have to settle for the same old politics. We do not have to accept the tired debate between the left and right, between Democrats and Republicans, between Congress and the White House. We can and we must declare a cease-fire — and move America forward."

At that conference -- where he told reporters he intended to serve his remaining 926 days as mayor -- Bloomberg received an endorsement of sorts from a fellow "post-partisan" liberal Republican with a reputation for reaching across the aisle: California Gov. Arnold Schwarzenegger.

"I myself think he would make an excellent candidate," Schwarzenegger said. "It's all about fixing problems, and creating a great vision for the future."

Asked about a possible Bloomberg/Schwarzenegger ticket -- as their mutual friend, billionaire investor Warren Buffet has urged -- Bloomberg said that "the governor and I never have had that conversation. But I can tell you how that conversation would go. There would be a fight to see who would be the presidential candidate and who would want to be the vice presidential candidate. He would want to wrestle for the top spot; I would want to check the Constitution."

(Schwarzenegger, born in Austria, is prohibited from ever serving as president, though the prohibition on someone not born in America serving as vice president is less definitive.)

How credible a Bloomberg candidacy would be is another matter.

"Mr. Bloomberg's really not gotten himself ready to run," said Bruce Cain, a political science professor at the University of California at Berkeley. "He doesn't have an organization, he hasn't studied the national issues. So even if he were to jump in to a crowded field with a lot of money, I don't think he'd be prepared and I don't know that there's room for it."

A former partner at Salomon Brothers and self-made media maven, Bloomberg, 65, spent $73 million of his own money in his race for mayor in 2001, winning 50 percent to 48 percent. He was reelected by more than 20 percentage points in 2005. During that time he has been praised for working closely with Democrats in City Council to improve education, housing, and to lessen New York City's output of greenhouse gases.

Bloomberg continues to say he has no current plans to run for president, and as recently as Sunday he was quoted in the New York Times downplaying the idea to columnist William Safire.

"A short, Jewish billionaire from New York?" Bloomberg said. "C'mon."

But, in fact, Bloomberg is seriously considering the idea. Worth more than $5 billion, he could spend less than a quarter of his net worth and be more than able to compete financially. But if Bloomberg runs, he doesn't want to make a point, as did fellow billionaire Ross Perot in 1992 and 1996. He wants to win. Whether or not he ultimately thinks he can will make all the difference in the world.

Arash Ghadishah and Avery Miller contributed to this report