President Obama and Massachusetts Sen. Edward M. Kennedy at yesterday’s forum on health-care reform.

MCT / Zbigniew Bzdak

WASHINGTON — President Obama yesterday launched his campaign to overhaul the nation’s medical system at a White House conference that featured expressions of support from across the industry and the political spectrum.

Mr. Obama declared after the half-day gathering of about 150 public officials, medical experts and business leaders from around the country that it had produced “a clear consensus that the need for health-care reform is here and now.”

The gathering also featured an emotional welcome for one of the nation’s most persistent champions of health-care reform, the ailing Sen. Edward M. Kennedy. There were hints, however, of battlelines forming among the dozens of interested groups represented at the event.

“Sir Edward Kennedy,” Mr. Obama said to laughter as a beaming Kennedy entered the East Room, cane in hand, to a warm ovation — with his son, Rep. Patrick J. Kennedy, among those applauding. “That’s the kind of greeting a knight deserves,” said the president, referring to the honor that the Queen of England recently conferred on the Massachusetts Democrat.

For his part, Kennedy reiterated the message of the day from Mr. Obama and his allies: that the moment for a sweeping reform of American medicine is at hand after decades of failed efforts.

“I’m looking forward to being a foot soldier in this undertaking,” Kennedy said, “and this time we will not fail.”

The tone of the conference, particularly the opening and closing sessions that featured Mr. Obama, was overwhelmingly cooperative. Senators and House members of both parties, leaders of businesses and unions, consumer advocates and executives of various wings of the American medical system all joined the president in expressions of willingness to compromise in order to change health care for the better.

One loud signal of a markedly changed political climate since 15 years ago — when elements of the insurance industry helped to kill President Bill Clinton’s overhaul of the system — came as Mr. Obama called on a leader of the nation’s health insurers, former Rhode Islander Karen Ignagni.

Ignagni told Mr. Obama that her industry has heard the public’s view on “what doesn’t work” in health care. “You have our commitment. We want to play. We want to contribute. We want to help pass health-care reform this year.” Coming from the president and chief executive of America’s Health Insurance Plans, the industry’s leading voice in Washington, the remark commanded attention in a roomful of experts on the difficult politics of health care.

The presence of such an array of allies and adversaries was reminiscent of the negotiations that — on a much smaller and simpler scale — helped Senator Kennedy and his son enact a bill last year to improve the insurance coverage of mental health — with the support of such lobbyists as Ignagni and of Republican allies who were on hand yesterday.

But between the lines, there were clear indications of battles to come — with Mr. Obama himself rebutting arguments from some of the key Republicans on hand.

When Mr. Obama took pains, for example, to recognize one potential adversary, Sen. Chuck Grassley of Iowa, the ranking Republican on the crucial Senate Finance Committee pleaded the case for insurance companies that fear that a government-subsidized medical plan would tempt businesses to stop providing health benefits — jeopardizing the private coverage business model. Many feel “that the government is an unfair competitor and that we’re going to get an awful lot of crowd-out, and we have to keep what we have now strong, and make it stronger,” Grassley said.

While pledging to see that Grassley’s worry “gets addressed,” Mr. Obama invoked the counterargument that government-subsidized medical coverage “gives consumers more choices” and thereby helps to “keep the private sector honest, because there’s some competition out there.”

The late-afternoon session with the president in the East Room capped a five-hour gathering. Much of it was devoted to meetings in rooms elsewhere in the executive complex, where participants hashed out aspects of the health-care overhaul in smaller groups and at length. At one session, Patrick Kennedy argued for “wellness” and prevention programs that help the mentally ill — who have higher morbidity rates from medical ailments than the general population.

As he convened the day’s final event, Mr. Obama read a series of excerpts from the afternoon’s remarks by various participants. One was a joking reference by Sen. Sheldon Whitehouse to a TV advertising campaign against Clinton’s plan to transform American medicine. In political circles, the ad became known for the fictional American couple — “Harry and Louise” — that it depicted, raising politically deadly doubts about the Clinton plan. Whitehouse played with the title to refer to another popular culture landmark, a movie about a pair of female desperadoes.

“We are past the ‘Harry and Louise’ moment,” Whitehouse said. “We’re at the Thelma and Louise moment. We are in the car, headed for the cliff.”

As he recounted the Rhode Island Democrat’s quip, Mr. Obama deadpanned to the effect that, in the movie, the car did indeed plunge over the cliff. “So I just want to be clear that’s not our intention here,” Mr. Obama said.

jmulligan@belo-dc.com