Pure Horserace: Bloomberg's Balloon

New York City Mayor Michael Bloomberg's departure from the Republican Party has set off the expected flood of speculation about a possible independent presidential campaign by the billionaire mayor. He's clearly been pushing the possibility with his speech this week in California where he decried politics as usual, his neatly-timed appearance on the cover of Time magazine and now this move.

Financially, he has more than enough resources to run a competitive campaign without even putting too much of a dent in his wallet. But does the rationale exist for a Bloomberg candidacy?

One of the most common themes, heard from Bloomberg supporters and echoed in the Mayor's press release last night, goes something like this: Republicans are being pushed too far to the right, Democrats too far to the left, leaving a void in the center of the body politic. Or, as Bloomberg put it, "any successful elected executive knows that real results are more important than partisan battles and that good ideas should take precedence over rigid adherence to any particular political ideology. Working together, there's no limit to what we can do."

Looking at recent history, the tenor of the political debate and the ways in which the current presidential candidates on both sides have sought to woo the bases of their party's, it's an understandable thought process. It's also one that seems to be taking hold at the moment in the two major parties as well.

Consider the two candidates considered front-runners — Hillary Clinton for Democrats and Rudy Giuliani for Republicans. Now, consider the candidates in both fields who have faced the most criticism from the liberal and conservative bases of their parties — Clinton and Giuliani.

For Clinton, the war in Iraq, her past support for it and her refusal to flatly apologize for her vote on it has caused her the most discomfort. Just this morning, according to The Associated Press, Clinton was heckled at a gathering of liberal activists when she mentioned Iraq. Add to that lingering feelings for the last Clinton administration — and its "triangulation" and centrist positions on things like welfare reform and NAFTA — and it's hard to argue that she represents only the "far left."

Giuliani has met with even more opposition from conservatives who find it hard, if not impossible, to envision supporting a candidate who supports abortion rights, has advocated gun control and gay rights and hails from New York City. The thrice-married former mayor's personal life and occasional in-your-face approach doesn't help endear him to red-state voters either.

Are Clinton and Giuliani special cases? Not really. Barack Obama's candidacy is not exactly based on liberal orthodoxy, either. His call to elevate the level of politics and bridge gaps is similar to, and more inspiring, than Bloomberg's businesslike call to get things done. Appealing to the better angels of our nature. Obama talks more like a transcendent candidate than an ideological one. John McCain's reputation as a maverick willing to buck his party on issues like campaign finance reform and immigration may eventually prove fatal to his candidacy but illustrates an independent streak despite some moves to the right.

Among the commonly accepted "Big Six" (soon to be seven) candidates in both parties, four of them seem not to fit Bloomberg's model of two parties being pulled to the extreme.

John Edwards, leading in Iowa but still stuck behind Clinton and Obama elsewhere, is emerging as the champion of the liberal-populist wing of the Democratic Party. Mitt Romney, who has surged in recent weeks, has worked hard to sooth conservative concerns on social issues and speaks the language of conservatives. Fred Thompson, who will enter the race firmly in the top tier, has attracted conservative support but still retains some of the independent glow of an outsider at the moment.

Chances are pretty good that two of these seven candidates will end up as the nominees of the two major parties. Just which ones may go a long way toward helping Bloomberg make a final decision. — Vaughn Ververs

No Empire? Recent polls among New York City residents have shown Bloomberg to be a more popular mayor than Giuliani, but the story is a little different when it comes to the presidential contest. A Quinnipiac University poll conducted prior to Bloomberg's switch in party affiliation finds him trailing in a three-way matchup with Clinton and Giuliani. As an independent, Bloomberg received just 16 percent in the poll of New Yorkers, far behind Giuliani at 29 percent and Clinton at 43 percent. Bloomberg does best Giuliani in New York City, 22 percent to 14 percent, but Clinton gets 54 percent of the Big Apple's support. — Vaughn Ververs

Newt Goes On The Attack… He hasn't announced whether he's running for president, but a new ad posted on YouTube by Newt Gingrich has all the hallmarks of a classic negative campaign ad. Opening with a shot of 9/11 hijacker Mohammad Atta, Gingrich uses the spot to detail his opposition to the immigration bill before Congress, referring to it as "McCain-Kennedy" three times — the bill is heavily based on legislation offered by Republican candidate John McCain and liberal Democratic Sen. Ted Kennedy. The spot also includes ominous background music and black-and-white imagery. "The new McCain-Kennedy immigration plan does not secure our borders and it does not protect our values," Gingrich says.

The ad — even if it's not entirely accurate — is a red-meat reminder to conservatives that a Gingrich candidacy remains on the horizon even as Fred Thompson's entry into the race, expected next month, could leave Gingrich without a vacuum to fill — he's said he'll decide on a run in late September.

If Gingrich had his presidential aspirations in mind when making the ad, however, his decision to target McCain is a little curious. Conservatives already know of McCain's support for the immigration bill, which some have cited as the cause for his bad fortunes of late. Any of the other top Republican candidates, especially Thompson, represents a bigger obstacle to Gingrich than McCain — perhaps he's saving attacks on them for later? — David Miller

While Mitt Romney Goes "Crazy": Romney is the only Republican candidate advertising in New Hampshire and Iowa, and recent polls in both states show the effort is paying off, with him holding (at least) comfortable leads over his rivals. Now, Romney is continuing the ad blitz with a new spot, "Work Like Crazy." In the ad, Romney makes several pledges on taxes: "Lower marginal tax rates for all Americans. Get taxes down. Make them simpler and flatter and lower," he says. "I've brought change to every institution I've touched. I'm going to work like crazy to go to Washington and bring change there."

Like a previous Romney ad in which he pledges to veto spending bills that outpace inflation, his latest commercial draws attention to Romney's fiscal policies. That might be a smart strategy — Giuliani has already claimed the "national security candidate" title, and focusing on money matters allows Romney to avoid discussing his relatively recent rightward shift on social issues. Plus, it allows him to distance himself from the ballooning spending and deficits of the Bush administration without sounding too harsh — and that's not crazy at all. — David Miller

Ups And Downs: A few weeks ago, a poll said Barack Obama and Hillary Clinton were tied. Now, the same polls says Clinton has returned to a double-digit lead. What gives? That's the question CBS News' director of surveys Kathy Frankovic examines in this week's installment of Poll Positions. Kathy notes that, at this early point in the election, public opinion isn't stable enough to yield consistent poll results, let alone allow for comparisons between different polls. Want to know more about what's behind those fluctuating numbers? Read today's column.

Editor's Note: Pure Horserace is a daily update of political news as interpreted by the political observers at CBSNews.com. Click here to sign up for the e-mail version.

By Vaughn Ververs and David Miller