Amid signs that he has successfully re-energised members of his own party with his combative and resolute address to a joint session of Congress late Wednesday on healthcare reform, President Barack Obama heads to the heartland tomorrow to try to close the deal with a still wary American public.

Speaking to a gathering of nurses in Washington yesterday, Mr Obama maintained the same note of urgency he struck on Capitol Hill.

“We have talked this issue to death,” he said. “The time for talk is winding down.” Democratic leaders were meanwhile predicting he would have a bill to sign this year.

Hoping to rebuild the momentum that was lost last month, when raucous town hall meetings grabbed the headlines, Mr Obama will pitch his plan in Minneapolis tomorrow in a sports arena that saw one of the biggest rallies of his presidential campaign last year.

While the Obama speech was stirring, it was a two-word contribution from a certain representative from South Carolina that may have done most to unify Democrats. It came from Joe Wilson, a Republican, who shouted “You lie!” when the President said illegal immigrants would not benefit under his plan.

Heckling may be common practice in parliamentary systems, but not in Washington. The gasps were enough to realign the chandeliers — and the look on the face of House Speaker, Nancy Pelosi, seated behind the President, could have frozen the Potomac River. “It demeaned the institution,” Vice President Joe Biden said yesterday.

Mr Wilson's unprecedented breach of etiquette drew censure from Democrats and Republicans alike, and he was swiftly obliged to issue a written apology. “I let my emotions get the best of me,” his statement said. However, there were calls yesterday for him to explain himself personally to the President. “He apologised quickly and I am appreciative of that,” Mr Obama said last night.

It was a brouhaha that embarrassed Republicans especially, who found themselves alternately courted by Mr Obama in his speech and chastised for using “scare tactics” to tear down his plan. He called out the “lies” told about so-called “death panels”, seen by many as a swipe at Sarah Palin, the former Alaska Governor, who has said such panels would decide when the old and sick would be left to die.

Addressing the gathering of nurses yesterday, the President complained again of “all the falsehoods that have been promoted not just by talkshow hosts but also by prominent politicians”. He added: “I will not permit reform to be postponed or imperilled by the usual ideological diversions.”

While leading Republicans criticised the President for a speech they considered overly partisan, the White House and leading Democrats were celebrating its impact. Aides pointed to a snap CNN poll that showed that among Americans who were watching Mr Obama on television, just over two-thirds said they favoured his plan, compared with 53% who said the same before he got up to speak.

That may be deceptive. While the main networks did broadcast the speech, there is no clear data on how many Americans actually watched it. An Associated Press poll released just before his address showed, by contrast, the steepness of the hill Mr Obama still has to climb. Just 42% of Americans approved of his work on health care, sharply down from July when 50% were on his side.

However Nancy Pelosi has insisted Mr Obama would prevail. “We'll pass healthcare insurance reform that will work for the United States,” she told reporters. “I'm confident the President will sign a bill this year.”

Republicans do not want to be seen to be obstructive for the sake of it. “Republicans want reform,” Senator John McCain said. “We know the system is broken, but we are very concerned about the cost.” Yet some in the party seemed more aggravated by the speech than eased by it.

“I found his tone to be overly combative and believe he behaved in a manner beneath the dignity of the office,”said Lindsey Graham, a Republican senator.

“However divided, Democrats surely will not humiliate a President of their own party by failing to pass anything.”