Poll: Michele Bachmann, Tim Pawlenty gain in GOP field

"I'm not sure that I would actually vote for Rick Perry, but I think if he would actually get in he would bring some valuable debate to the issues," she said. Overall, Renfro said, "I'm not too impressed" with the GOP field.

Among other poll details:

—Republicans still give Romney the highest favorability rating among announced candidates, at 61 percent. Palin, who's keeping everyone guessing about her intentions, is holding steady, too, with a 63 percent favorability rating.

—Bachmann's favorability rating jumped from 41 percent to 54 percent among Republicans. A third still have no opinion about her, and it's too soon to tell if her boost will endure or was a June phenomenon.

—Huntsman, who announced his candidacy this week but still is relatively unknown nationally, had a 23 percent favorability rating among Republicans. He's gotten better known — 59 percent had no opinion about him in the latest poll, down slightly from 66 percent a month earlier. But the result was an increase in those with an unfavorable opinion, from 11 percent to 17 percent, with a greater uptick among tea party supporters.

—Pawlenty, one of the first to get into the race, saw his favorable ratings rise 10 percentage points to 43 percent. His support among tea party backers was up 11 points.

The poll was conducted June 16-20 by GfK Roper Public Affairs and Corporate Communications. It involved landline and cellphone interviews with 1,001 adults nationwide and had a margin of sampling error of plus or minus 4.1 percentage points. The survey included 429 Republicans, and that subset had a larger, 6.2 percentage point margin of error.

Associated Press News Survey Specialist Dennis Junius contributed to this report.