PORTSMOUTH, N.H. â Hoping to blunt the momentum of critics, President Barack Obama went on the offensive in support of his health care plan Tuesday, urging the country not to listen to those who seek to "scare and mislead the American people." "For all the scare tactics out there, what is truly scary is if we do nothing," Obama told a friendly town hall audience. Retooling his message amid sliding support, Obama poked at critics who he said were trying to "scare the heck out of folks." He said there should be a vigorous debate over health care, but "with each other, not over each other." "Where we disagree, let's disagree over things that are real, not these wild misrepresentations that don't bear any resemblance to anything that's actually being proposed," Obama said, trying to wrest back control over a debate at the core of his political agenda. Addressing a town hall in New Hampshire, Obama also flayed the insurance industry in an attempt to attract a vital â and skeptical â audience: the tens of millions of people who already have health insurance and are just fine with the care they get. He said the overhaul is essential to them, too, contending it is the way to keep control in their hands. "Your health insurance will be there for you when it counts, not just when you're paying premiums," Obama said to applause at a local high school. Obama said "after all the chatter and shouting and the noise," Americans will soon have more and cheaper options for health care. "I don't think government bureaucrats should be meddling. But I also don't think insurance company bureaucrats should be meddling," he said. Obama's pitch came as angry crowds have put many lawmakers on the defensive as they try to talk about health care with their constituents, leading some to replace public forums with teleconferences or step up security to keep protesters at bay. The disturbances come at a critical time as lawmakers â mostly Democrats â return home for the August recess and host the meetings to boost support to overhaul the nation's costly health care system. The president accused critics of creating "boogeymen." "Spread the facts. Let's get this done," Obama implored the crowd. The questions Obama faced were straightforward and there were no immediate outbursts. During the middle of the civil back-and-forth, one man identified himself as a Republican and said, "I don't know what I'm doing here." The Democratic president said he was happy to have him in attendance. Toward the end of the session, Obama went so far as to ask for someone to give him a skeptical question. The best he got were queries about why he doesn't chastise Congress more and where the nation would find the additional doctors and nurses it needs. Heading toward a pivotal fall debate, Obama is scrambling to get lawmakers and the public behind what would be the most ambitious and costly changes to the health care system in decades. Obama reiterated that the plan would be paid for without adding to the nation's soaring deficit. His broader mission amounted to try to shoot down what he described as erroneous claims that have risen as the debate in Washington and the nation has developed. He singled out the charge that the Democratic health care legislation would create "death panels" to deny care to frail seniors. Former Republican vice-presidential candidate Sarah Palin has said the Democrats' legislation includes "death panels" that could deny care. Obama declared that a provision that he said had caused the uproar would only authorize Medicare to pay doctors for counseling patients about end-of-life care, living wills, hospice care and other issues, if the patients wanted it. It would not "basically pull the plug on grandma because we decided that it's too expensive to let her live anymore," as Obama put it. The president said lawmakers "very sensibly thought this was something that would expand people's options." The people Obama called on for questions asked him largely about their personal medical concerns and how any new law would affect them. "We're not talking about cutting Medicare benefits," he said, trying to reassure one questioner. Obama sought to dispel talk that his ultimate goal is a single-payer federal health care system, like that in countries such as Canada. In 1996, when he was running for the state Senate in Illinois, he was asked on a questionnaire whether he supported a single-payer health plan. The response was, "Yes in principle." During Tuesday's town hall, he said, in answer to a question from a self-described Republican, that he doesn't believe such a system would be workable for the United States. "For us to transition to a system like that I think would be too disruptive," Obama said. He also disputed the notion that adding a government-run insurance plan into a menu of options from which people could pick would drive private insurers out of business, in effect making the system single-payer by default. As long as they have a good product and the government plan has to sustain itself through premiums and other non-tax revenue, private insurers should be able to compete with the government plan, Obama said. "They do it all the time," he said. "UPS and FedEx are doing just fine. ... It's the Post Office that's always having problems."