President Barack Obama today urged the US Congress to enact sweeping health care legislation, declaring the "time for bickering is over" and the moment has arrived to help millions who have insurance and many more without it.
His nationally televised speech to a joint session of Congress comes as Mr Obama's popularity is falling, opposition Republicans are on the attack and his fellow Democrats are divided about what kind of plan to pursue.
"I am not the first president to take up this cause, but I am determined to be the last," Mr Obama said.
Health care has become the definitive issue for Mr Obama, just nine months after he took office amid enormous expectations at home and abroad.
His success or failure may determine whether he has the political clout to press ahead on issues like climate change, arms control and the Afghanistan war. It is also likely to shape next year's congressional elections.
Mr Obama said there is widespread agreement on about 80% of what must be included in legislation.
And yet, criticising opposition Republicans without saying so, he added: "Instead of honest debate, we have seen scare tactics" and ideological warfare that offers no hope for compromise.
He blasted Republicans for spreading the "cynical and irresponsible" charge that his legislation would include "death panels" with the power to hasten the death of senior citizens.
"Well, the time for bickering is over," Mr Obama said. "The time for games has passed. Now is the season for action."
The venue of today's speech underscored the importance of the issue. Besides the annual State of the Union address, presidents seldom speak to a joint session of Congress, consisting of politicians from both chambers.
But the speech was aimed as much at the millions of Americans watching from home, many of whom have become disillusioned with Mr Obama's handling of health care.
An Associated Press-GfK poll released hours before the address showed that disapproval of Mr Obama's handling of health care has jumped to 52%, from 43% in July.
Mr Obama's overall approval rating has also suffered a blow. The survey showed that 49% now disapprove of how he is handling his job as president, up from 42% who disapproved in July.
Mr Obama appealed for a health care overhaul that provides new and crucial protections for people who already have insurance, affordable access to coverage to those without, and reduced spending for families, businesses and government.
Mr Obama spoke in favour of an option for the US government to sell insurance in competition with private industry. But he said he was open to alternatives that create choices for consumers - a declaration sure to displease its liberal supporters.
Mr Obama said he remains ready to listen to all ideas but added in a clear reference to Republicans, "I will not waste time with those who have made the calculation that it's better politics to kill this plan than to improve it."
In an unusual outburst from the Republican side of the House chamber, Representative Joe Wilson of South Carolina shouted out "You lie" when the president said illegal immigrants would not benefit from his proposals.
The president paused briefly and smiled, but from her seat in the visitor's gallery, first lady Michelle Obama shook her head from side to side in disapproval at the interruption.
Some Americans who have suffered from high costs and insurance practices sat near Michelle Obama during the speech, and Mr Obama mentioned them in his remarks.
Vicki Kennedy, the widow of Senator Edward Kennedy, was there. Mr Kennedy, who died last month, had made health care a career-long cause, and Mr Obama spoke movingly of his efforts.
Mr Obama drew a standing ovation when he recounted stories of Americans whose coverage was denied or delayed by their insurers with catastrophic results.
"That is heartbreaking, it is wrong, and no one should be treated that way in the United States of America."
Mr Obama made health care reform a priority when he ran for president last year. The United States is the only developed country without a universal programme of health care. As many as 50 million Americans lack health insurance.
Responding to the president's speech on behalf of Republicans, Representative Charles Boustany of Louisiana said the country wants Mr Obama to instruct Democratic congressional leaders that "it's time to start over on a common-sense, bipartisan plan focused on lowering the cost of health care while improving quality.
"Replacing your family's current health care with government-run health care is not the answer," said Mr Boustany, a former cardiac surgeon.