Anyone for a third party?

No, not on top of Christmas and New Year's. A third-party candidacy for president - and this one comes with a warning: It won't be easy, at least not for three top-mentioned possibilities, Ron Paul, Donald Trump and New York City Mayor Michael Bloomberg.

The latest ABC News/Washington Post poll finds that each would have significant challenges were he to undertake the task of mounting a third-party candidacy. Among them:

Americans divide evenly in basic favorable  versus  unfavorable views of Paul, unchanged from last month, and Paul faces serious questions even in his own party both on his personal qualifications and the policies he'd pursue if elected

Trump, while more popular than Paul among Republicans, and the best known of the three, is the least popular overall. More Americans view him unfavorably than favorably, by 48 percent to 40 percent - never a good position for a public figure.

Bloomberg is much less  known - 44 percent of Americans haven't formed an opinion of him - and, like Paul, gets just an even split among those who have. He's most popular among liberal Democrats, a group that comprises only 12 percent of the public overall.

That's not to say third-party candidates can't cause mayhem. In an ABC/Post poll released earlier this week, Mitt Romney and Barack Obama were dead even among registered voters, 47-47 percent. But when Paul was added as a theoretical independent candidate, he pulled 21 percent support, mainly out of Romney's hide, putting Obama 10 points ahead.

Third-party candidacies often arise in times of economic discontent, and that certainly applies to current times. In an expression of discontent with the major parties, more Americans have identified themselves as independents than as either Democrats or Republicans for nearly two and a half years - the longest run of its kind since ABC/Post polling started in 1981.

That said, an ABC/Post poll completed Oct. 30 found interest in a nonparty candidate to be broad but not deep. Sixty-one percent responded favorably to the idea, but far fewer, 25 percent, endorsed it strongly. And overcoming major-party allegiance is a tough task. The best showings by third party candidates in the last century have been Teddy Roosevelt's 27.4 percent in 1912, Ross Perot's 18.9 percent in 1992 and Robert "Fighting Bob" LaFollette's 16.6 percent in 1924. None came close to actually winning.

Doing well takes a popular candidate, and as noted, Paul, Trump and Bloomberg all have challenges. Here's a rundown of their ratings in the latest ABC/Post favorability survey, produced for ABC News by Langer Research Associates:

PAUL - Thirty-two percent of Americans have a favorable opinion of Paul, but 35 percent view him unfavorably; another third have no opinion. Paul's only 8 points above water in his own party - 43 percent of Republicans view him favorably, 35 percent unfavorably - moving to an even split among independents and a 19-point negative score among Democrats.

Paul's lost ground in the past month among "very" conservative Americans, slipping from 44 percent favorable in late November to 35 percent now. He's made that up among "somewhat" conservatives and moderates, therefore holding even overall.

Paul, moreover, has problems beyond favorability. As noted in the ABC/Post political poll earlier this week, only 37 percent of Republicans and Republican-leaning independents think Paul has the personality and temperament to serve effectively as president, only 42 percent think he'd pursue policies most Americans would find acceptable and 45 percent see his opposition to U.S. military intervention as a major reason to oppose his candidacy for the GOP presidential nomination. Paul hasn't said if he'd run as an independent should he lose the party race.

TRUMP - In contrast to Paul, Trump has a 20-point positive spread, 56-36 percent favorable-unfavorable, among Republicans. But his ratings are more sharply divided among political groups. Trump's favorable score drops by 15 points among independents, and falls further, to 30 percent, among Democrats, with 61 percent seeing him unfavorably.

Trump, similarly, goes from a 52 percent favorable among very conservative Americans to half that, 27 percent, among liberals. And even among very conservatives, 41 percent see him unfavorably, contributing to his net negative rating overall.

The wealthy Trump has a 19-point popularity deficit among people in $100,000-plus households. And he's particularly unpopular, six in 10 unfavorable, among senior citizens and college graduates. His unfavorable ratings in these groups rival his among Democrats and liberals.

BLOOMBERG - Bloomberg's ratings are more evenly balanced in partisan terms - an 8-point gap between Democrats (36 percent see him favorably) and Republicans (28 percent). That compares with an 18-point gap for Paul between these groups, and a 26-point spread for Trump.

Bloomberg is more liked than disliked among liberals and moderates (12-point positive favorable-unfavorable gaps) and is essentially even among those who say they are somewhat conservative. Only very conservatives are more negative than positive, 40-26 percent. He's much better known - and better-liked - in the Northeast than elsewhere.

METHODOLOGY - This ABC News/Washington Post poll was conducted by landline and cell phone Dec. 14-19, 2011 among a random national sample of 1,019 adults. Results have a margin of sampling error of 4 points. The survey was produced for ABC News by Langer Research Associates of New York, N.Y., with sampling, data collection and tabulation by SSRS/Social Science Research Solutions of Media, Pa.