The tumultuous health care debate that brought rumors of death panels and socialism has spun off a catalog of myths that will likely keep growing as President Obama and all sides battle toward the midterm elections this fall.

At a White House signing ceremony Tuesday, Obama ventured the hope that Americans on all sides will judge the legislation for what it actually says and does. “When I sign this bill,” he declared, “all of the overheated rhetoric over reform will finally confront the reality of reform.”

But, facts are stubborn, as the saying goes, and myths about the legislation are likely to persist as well. And a lot of people don’t agree on which is which.

“People have taken away from the debate a number of beliefs about the bill that are very difficult to shake based on objective reports,” said Robert Blendon, a Harvard public health professor who follows opinion trends.

Here’s a look at some of the myths and realities, from both sides of the issue:

Myth: Obama has put the nation on a slippery slope toward socialism.

Fact: Government’s role in health care has been steadily growing since Medicare and Medicaid were established 45 years ago. Even if Republicans were to repeal this bill, government would still be on track to pick up more than half the nation’s health care tab by 2012, according to a report last month from Medicare.

“The Republican myth is that the government is for the first time going to take over the health care sector,” said economist Joe Antos of the business-oriented American Enterprise Institute.

“The takeover was probably largely accomplished in 1965 with the creation of Medicare and Medicaid. Since the early days, Medicare has called the shots on a lot of policy issues that private insurance fell in line with.”

Still, the law will undoubtedly expand federal influence. Sen. Judd Gregg, R-N.H., said Tuesday it will lead to the “quasi-nationalization of the health industry.”

Underline “quasi.” Democrats dropped their idea of a government insurance plan to compete with private carriers. So any socialization will be channeled through Wellpoint, UnitedHealthcare and other private insurance giants.

Myth: Health care overhaul is going to lower your insurance premiums.

Fact: The president says that once competitive insurance markets open for business, in 2014, individuals buying coverage comparable to what they have today will pay 14-20 percent less. Family coverage costs about $13,400 a year, so that could be real money.

But Obama’s assurance is based on a selective reading of a Congressional Budget Office report that found most individuals would probably buy better, more expensive coverage than what’s available today.

And Obama skips over an important caveat: The budget office didn’t say premiums would be lower than currently. It said premiums for some people would be lower than they would have been without the bill. Others’ premiums would be higher.

With the U.S. population getting older, and science pushing the technological envelope, there’s very little reason to think premiums will fall. The best Obama can hope for is to slow the pace of increases.

Myth: You will be forced to pay for other people’s abortions.

Fact: Only if you join an insurance plan that covers abortion. In that case, the costs of paying for abortions would be spread over all enrollees in the plan — the same way other medical procedures are handled, except a policyholder would have to write a separate check for it.

Timothy Jost, a law professor at Washington and Lee University, said people who don’t want to pay for abortion could simply pick a plan that doesn’t offer it.

Myth: The Democratic bill will lead to government health care rationing.

Fact: The legislation sets up a research center to compare the effectiveness of medical treatments, and critics fear that bureaucrats will start issuing justifications for denying patients access to the latest medical technology.

Republicans as well as Democrats had previously called for a major investment in such research to help make sense of what treatments, medications and technologies are worth the cost.

The legislation specifies that the research findings cannot be used to impose mandates, guidelines or recommendations for payment, coverage or treatment — or used to deny coverage.

Acceptance of the research is likely to be slow in coming, and the medical community — not government and insurers — will probably take the lead in vetting it.

Myth: The American people have already rejected Obamacare.

Fact: Some polls show a majority oppose the bill, but most surveys find the public about evenly divided. Blendon, the public opinion expert, believes it’s premature to say the public has rejected it. Many individual components — doing away with denials for pre-existing conditions, tax credits to help pay premiums, insurance purchasing pools — are widely popular.