House Speaker Nancy Pelosi's (D-Calif.) favorable ratings are lower than ever, a new poll found Wednesday, as more Democrats distance themselves from her.

Twenty-nine percent view the Speaker favorably, while an all-time high of 56 percent of U.S. adults view her unfavorably, a new Gallup poll found.

Those are the worst numbers for Pelosi in the time since Democrats won back the House and she became Speaker in early 2007. She had a 44-22 percent favorable rating at that time.

Her latest numbers also represent a drop-off from earlier this year: Pelosi was seen net-negatively by a 15 percent margin in Gallup's last poll of her popularity, a gap that's widened to 27 percent now.

The slipping favorability numbers for the Speaker come as a growing number of Democratic incumbents and candidates are showing cracks in her base of support. A steady trickle of Democrats have said that they wouldn't vote for her again as Speaker, and an even larger number have refused to commit to supporting her. Rep. Mike McIntyre (D-N.C.) said that he'd heard she wouldn't seek another term as Speaker, though Pelosi has shown indications that she would do so if Democrats retain the House.

The man who would be running for Speaker if Republicans win back the House, by contrast, has net-positive favorability ratings.

House Minority Leader John Boehner (R-Ohio), the would-be Speaker under a GOP majority, has a 31-27 percent approval rating, the Gallup poll found.

But 42 percent of U.S. adults said they had never heard of the Cincinnati-area Republican, or had no opinion about him. That's only a 2 percent increase in the number of Americans who say they're familiar with Boehner, a figure that has to be troubling for the White House.

The Obama administration led an effort earlier this fall to elevate Boehner in a negative way and familiarize voters with the man who would be Speaker if the GOP makes enough gains in the Nov. 2 elections. The Gallup figures call into question whether that was a good strategy, especially as Democrats have shifted their attacks now to focus on groups that are spending on behalf of Republicans, as well as corporate influence in elections.

The Gallup poll, conducted Oct. 14-17, has a 4 percent margin of error.