Sarah Palin is the most polarizing of the possible 2012 Republican presidential candidates, according to an Associated Press-GfK poll.

Former Arkansas Gov. Mike Huckabee garnered the highest favorability rating, followed by former Massachusetts Gov. Mitt Romney.

Also noteworthy: When it came to Minnesota Gov. Tim Pawlenty, Mississippi Gov. Haley Barbour, Sen. John Thune (R-S.D.) and Indiana Gov. Mitch Daniels -- most voters didn't know who they were.

No Republican has formally announced a challenge to President Obama but there are several names in the mix.

Palin, the former Alaska governor and 2008 vice presidential nominee, is the best-known and most divisive, according to the poll, which found 46 percent view her favorably, 49 percent unfavorably, and 5 percent don't know enough about her to say.

Here's how the other candidates measured up:

Huckabee: 49 percent favorable, 27 percent unfavorable, 25 percent had no opinion.

Romney: 46 percent favorable, 31 percent unfavorable with about a quarter having no opinion.

Pawlenty: 28 percent favorable, 13 percent unfavorable, 59 percent had no opinion.

Barbour: 27 percent favorable, 14 percent favorable, 58 percent had no opinion.

Daniels:  24 percent favorable, 13 percent unfavorable, 63 percent had no opinion.

Thune: 20 percent favorable, 10 percent unfavorable and had 70 percent no opinion.

The AP-GfK Poll was conducted Nov. 3-8. It involved landline and cell phone interviews with 1, 000 adults nationwide and had a margin of error of plus or minus 4.1 percentage points.