ASHINGTON, Dec. 19 - Republicans, who favor limits on medical malpractice lawsuits, have stories about towns in Ohio with no obstetricians to deliver babies and places in southern Illinois with no neurosurgeons - the doctors having taken down their shingles because of the high cost of malpractice insurance.

Democrats, who oppose restrictions on lawsuits, have their own tales: about the surgeon in Wisconsin who performed an unnecessary double mastectomy on a woman, for instance, or the 2-year-old boy in Nebraska who died from dehydration because of a hospital's neglect.

With legislation on Social Security and taxes still in the early stages of development, malpractice is likely to be one of the first of President Bush's campaign issues that Congress takes up in the new year. "We've done it before, and it's a pretty well-worn path," said John P. Feehery, the spokesman for Speaker J. Dennis Hastert.

Seven times since Republicans gained control of Congress in 1995, the House has passed legislation to curb medical malpractice claims. Each time the measure has been blocked in the Senate, falling well short of the 60 votes needed to bring the matter to a vote.

With their larger majority in the Senate after last month's elections, Republican leaders say they expect to prevail next year.

"This is a majority priority," Senator Bill Frist of Tennessee, the majority leader, said in an interview. "I am convinced that over this Congress, we will have a meaningful federal solution."

Democrats say they still have the votes to stop the legislation. "With the new configuration, I'm not going to assume anything," said Senator Richard J. Durbin of Illinois, a staunch opponent of limits on malpractice suits who will be the assistant Democratic leader in the new Congress. But Mr. Durbin observed that proponents of such limits had only 48 and 49 votes the two times the matter was before the Senate this year and added, "It seems to me the shift shouldn't change the outcome."

In the Senate this year, only one Democrat, Zell Miller of Georgia, favored limits on lawsuits, and he did not run for re-election. Three Republicans opposed limits: Michael D. Crapo of Idaho, Lindsey Graham of South Carolina and Richard C. Shelby of Alabama, who were courtroom lawyers before they entered politics.

Republicans picked up four seats in last month's election. But one of the four, Mel Martinez of Florida, was a leading trial lawyer in Orlando who helped defeat a measure before the Florida Legislature in 1988 that would have put a cap on malpractice damage awards.

The last time the House voted on the issue was in March 2003. By a vote of 229 to 196, it passed a bill that would have put a $250,000 ceiling on jury awards for pain and suffering caused by medical malpractice, limited punitive damages and restricted the contingency fees plaintiffs' lawyers could charge.

Dr. Frist said the political calculus would change this year because of Mr. Bush's commitment and strong public support for restricting malpractice awards.

In his re-election campaign, Mr. Bush emphasized curbs on medical liability.

In his third debate with Senator John Kerry, for example, Mr. Bush asserted that malpractice lawsuits and "the defensive practice of medicine" by wary doctors and hospitals cost the government $28 billion a year and "our society between $60 billion and $100 billion a year."

Independent analyses suggest that the president's cost estimates were exaggerated.

The nonpartisan Congressional Budget Office reported in January that malpractice costs were less than 2 percent of overall health care spending and that even a 30 percent reduction in malpractice costs would lower health care spending by less than 0.5 percent.

Few other policy issues are so driven by anecdote, hyperbole and campaign donations.

Dr. Donald J. Palmisano, whose term as president of the American Medical Association ended in June, said in an interview that "as much as 50 or 60 percent" of the cost of malpractice insurance could be attributed to unjustified awards to plaintiffs for "noneconomic damages," which usually means pain and suffering.

The medical association gave more than $2 million to candidates in this year's elections, mostly to Republicans running for the House and Senate and organizations supporting them. Other associations representing doctors, dentists and hospitals gave millions more.

Todd A. Smith, president of the Association of Trial Lawyers of America, said that the high insurance cost had "nothing to do with noneconomic damages" and "everything to do" with greedy insurance companies.

The trial lawyers' association donated $2.5 million to this year's candidates, almost all of it to Democratic candidates and their supporting organizations. Lawyers and law firms gave millions more.

The actual size of malpractice awards is impossible to calculate, since so many suits are settled before they reach trial. The Congressional Budget Office reports that 15 claims are filed for every 100 doctors each year and that about a third of the claims result in an insurance payment.

Public opinion is clearly on the side of curbing malpractice damages. A Gallup poll last year found that about three-quarters of those surveyed supported "a limit on the amount patients can be awarded for their emotional pain and suffering."

The National Conference of State Legislatures says that 34 states have enacted such caps. The experience in those states suggests that limits on awards do result in lower insurance costs.

For example, according to Medical Liability Monitor, a newsletter that tracks malpractice issues, obstetrician-gynecologists in California, which has had limits on malpractice claims since 1975, pay no more than $90,000 a year for malpractice insurance, while those in Illinois, which has no restrictions, pay as much as $230,000.

But the newsletter's data suggest that legal limits are not a cure-all. In Minnesota, for instance, which has no such limits, the annual malpractice premium for a general surgeon can be as low as $11,000. But in Michigan, which has limits, general surgeons pay more than $190,000.

The Congressional Budget Office concluded that a measure like the one the House passed last year would lower insurance premiums nationwide by 25 percent to 30 percent.

But the budget office questioned whether this would actually solve the problem of doctors abandoning certain communities. It cited a study by another nonpartisan agency, the Government Accountability Office, which found some places where people's access to emergency surgery and obstetrics had indeed become limited because doctors had left. But it then went on to say that many reported doctor shortages could not be substantiated or did not result primarily from the cost of malpractice insurance.