CHICAGO (AP) — The nation's largest group of doctors began their annual meeting as a potential obstacle to President Obama's health care overhaul. After a big pep talk from Obama himself, they ended it Wednesday by signaling they won't close the door on one of his key proposals, a public health insurance plan to compete with private insurers.

While the Obama administration would have preferred a strong endorsement, the vote by American Medical Association doctors is a victory of sorts for the White House and the group will continue to be a player in the health care reform efforts.

"They're going to be at the table," said Paul Ginsburg, president of the Washington-based Center for Studying Health System Change.

Obama's trip to Chicago earlier this week shows how much he values the doctors' support.

The AMA is known to be a conservative bunch and has clashed with previous administrations' attempts to shape health policy. Its membership has been dwindling for years, down to about one-fourth of the nation's physicians, but it remains a visible lobbying presence in Washington.

The group acted Wednesday in its typically cautious fashion on the health care reform effort, heeding concerns of its most conservative members while indicating it wants to be a team player and work with Obama. But critics say it missed a chance to go bolder and signal clear support for the public plan concept.

"The AMA did not close doors. The AMA said we will evaluate all proposals in light of our principles," said Dr. Nancy Nielsen, the AMA's immediate past president.

Nielsen, whose term ended Tuesday night, urged the more than 400 policy-making delegates before the vote to avoid language that could be interpreted as an endorsement of any public plan.

Delegates followed her advice and declared support for "health reform alternatives that are consistent with AMA principles," which include freedom to choose health insurance and universal access for patients.

Nielsen said the new language could include a public plan, but that it doesn't commit the AMA to endorsing any or all public options. The adopted measure now represents official AMA policy on this aspect of health care reform. Changes to any policy generally can't be made until the delegates meet again in November.

Some doctors at this week's meeting wanted the group to oppose any public insurance proposal. They likened the concept to communism, putting government in charge of health care and forcing doctors and patients into plans. Some said it would only lead to a single-payer system that the AMA has long opposed. And others who think doctors aren't paid enough under two existing public programs, Medicare and Medicaid, worried a new public plan would be no better.

But Obama has said a public option would simply provide coverage for those without other insurance. And his speech on Monday converted some skeptics.

"If you like your doctor, you will be able to keep your doctor, period. If you like your health care plan, you will be able to keep your health care plan, period," Obama said to applause.

Some in the crowd of more than 2,000 mostly doctors booed when Obama said he doesn't support caps on how much money patients harmed by doctors can seek in medical malpractice lawsuits. But the audience was largely receptive during his nearly hour-long speech.

Doctors greeted the president like a rock star, standing on tiptoes and clicking cell-phone cameras in between loud applause. They gave him several standing ovations.

Dr. Nicholas Vedder, a Seattle plastic surgeon, said several colleagues told him the president's speech persuaded them to support his public plan concept.

Vedder, who supported the idea before the speech, said the AMA's vote shows "they've seen the writing on the wall."

"To the extent we can help shape the policy rather than oppose, American medicine will be better served," Vedder said.

Dr. Ted Epperly, a family physician from Boise, Idaho and public-plan supporter, said he's "philosophically troubled" the AMA didn't take a stronger stand, but that it was better than nothing.

And Dr. Michael Goldrich, a former AMA board member who remains unconvinced on the public option, said he nonetheless supports the delegates' vote and AMA leaders' desire to have "a meaningful dialogue with the administration."

"Everything that happened at this meeting," Goldrich said, "really reflects AMA's genuine desire ... to try to achieve effective health system reform."