Check out the trend lines for Obama and Palin:
Among the chief problems for Palin is that while Republicans generally like her, everyone else tends to lean toward loathing her. The TPM Poll Average gives her a national favorability rating of 37.2%, with an unfavorable rating of 51.7%.
[TPM SLIDESHOW: Governor Sarah Palin: A Long Goodbye]
Compare that to Romney, who has a 38.0% approval rating in the TPM Poll Average, but an unfavorable rating of just 29.3%. That leaves roughly 30% of Americans who don't know Romney well enough to form an opinion of him. Most voters have already made up their minds about Palin.
Further, most of the country does not even think Palin is qualified to be President. According to a Washington Post-ABC News poll from October, only 27% of Americans said Palin was qualified to be President, versus 67% who said she was not.
Palin can't even find love from her home state, where only 33% of respondents to an October 31 PPP poll viewed her favorably, versus 58% who viewed her unfavorably. In the same poll, 70% of respondents said they did not want Palin to run for President.
If Palin does wind up running, there are some ominous signs for how she'd perform in some important swing states.
In the last month, PPP has polled eight swing states - Montana, Virginia, North Carolina, Missouri, Michigan, Minnesota, Ohio, and Wisconsin - and in all of them, Palin fared worst among the polled Republican candidates. In a December 1 poll of Missouri, PPP found Gingrich, Huckabee, and Romney all leading Obama; the same poll had Palin trailing by three points.
PPP's Tom Jensen notes that Palin is the only one of the prominent Republican candidates who would fare worse than John McCain in 2008, and that she would allow Obama to pick up at least one state he lost two years ago.
Of course, it's still very, very early -- especially considering that no one has officially announced a campaign yet. But if Republican voters hope to make Obama a one-term President, the early polls show that Palin just doesn't seem to be a good bet.