WASHINGTON —As President Obama’s effort to overhaul the health care system seems to hit one roadblock after another in Congress, he is counting on Senator Max Baucus, a political shape-shifter and crafty deal-maker who is not fully trusted by either party, to help him clinch his top domestic priority.
Other Democratic lawmakers can claim more experience on health issues, or can boast of far more legislative achievements. But more than anyone else, Mr. Baucus, the Montana Democrat and centrist chairman of the Senate Finance Committee, may have the best shot at getting his committee’s measure passed into law.
In some ways, he is an accidental point man. Senator Edward M. Kennedy, the Massachusetts Democrat and health committee chairman, who has worked on health issues for 40 years, is sidelined by brain cancer.
Senator Christopher J. Dodd of Connecticut, Mr. Kennedy’s fill-in, has so far been unable to win Republican support for the more liberal bill before the health committee.
Income tax problems prevented Tom Daschle, the former Senate majority leader who clashed bitterly with Mr. Baucus over health issues, from becoming secretary of health and human services, which might have given him the dominant role on Capitol Hill.
Meanwhile, House Democrats, who put forward their own draft legislation last week, have virtually no working relationship with their Republican colleagues.
All of that has left Mr. Baucus, 67, front and center, with the future of the health system largely in his hands. “If there is any chance we can do a bipartisan bill, it has to be in the Finance Committee,” said Senator Harry Reid of Nevada, the majority leader.
Mr. Baucus, in an interview, said he had been preparing for this role since he was elected to the Senate in 1978, and viewed this as his moment — and Montana’s — to make history.
“I think I’m the luckiest guy in the world,” he said in an interview in his office. “Here I am representing Montana in the United States Senate. I am at the point to be able to do something really significant, really meaningful, and it must be done.”
His interest in the issue is not new. In 2003, as Mr. Baucus was running a 50-mile ultramarathon, he lost his footing and tumbled, gashing open his head. He got up and kept running to the finish, looking so ghastly with blood caked over his right eye that a young boy cheering on runners from the sidelines refused to give him a high-five.
Two months later, Mr. Baucus needed emergency brain surgery to stop bleeding caused by the fall, giving him an up-close look at the health care system.
The surgery was done at the Mayo Clinic in Scottsdale, Ariz., which is known for delivering high-quality care at a moderate cost. But it was also done out of network, leaving Mr. Baucus with thousands of dollars in bills not covered by his gold-plated federal health insurance plan.
Since then, he and Mayo Clinic doctors have carried on a running conversation about how to encourage high-quality, rather than high-quantity, care.
Mr. Baucus’s bill is likely to allow the federal government to set minimum standards for provider networks so consumers are not surprised by high out-of-network costs, as he was.
As Mr. Baucus pursues his goal, one challenge is his own reputation. Some Democrats think he betrayed the party in 2001 when he supported President George W. Bush’s tax cuts, and in 2003 when he was one of two Democrats to help Republicans pass a Medicare prescription drug plan.
But while those episodes made Democrats suspicious, he is not completely trusted by Republicans. This year, he played a leading role in expanding the Children’s Health Insurance Plan, largely trampling critics like Senator Charles E. Grassley of Iowa, the senior Republican on the Finance Committee and one of his closest friends in the Senate.
Some Republicans say they fear that Mr. Baucus is stringing them along and will be outmuscled by more liberal power brokers like the House speaker, Nancy Pelosi.
Even Mr. Reid, a good friend, concedes that Mr. Baucus can be unpredictable, recounting in his autobiography a fear that Mr. Baucus would help Mr. Bush privatize Social Security. In the end, Mr. Baucus led Democrats in defeating Mr. Bush’s plan.
Mr. Baucus takes great pride in working with Republicans, especially Mr. Grassley. Last week, as Republicans pummeled Mr. Dodd over the cost of his bill, Mr. Baucus huddled with some of those critics, including Mr. Grassley, to develop a bill that Republicans could support.
Mr. Baucus also delayed his first public drafting session until after the Fourth of July to work on lowering the bill’s cost.
Soft-spoken but tenacious, Mr. Baucus in recent weeks successfully strong-armed several lobbying groups into muting their criticism of his legislation, part of a concerted strategy of assuring interest groups that they had his ear as long as they did not chew on it.
Some Republicans called it heavy handed. “They’re literally being intimidated,” said Senator John Cornyn, Republican of Texas.
Even as Mr. Baucus has tamped down criticism, he has continued collecting campaign contributions from industry interests, including drug companies and insurers.
In many ways, the push to overhaul health care is a legislative ultramarathon. And however improbable it might seem, Mr. Baucus, son of a rancher and great-grandson of a member of the Cowboy Hall of Fame, is setting the pace.
“He is perfectly positioned to do this,” said Jim Messina, a longtime aide, fellow Montanan and close friend of Mr. Baucus who is now a White House deputy chief of staff. “He wants it. He cares about it. He has done the homework. This is not a flies-running-to-the-light political issue of the moment. He was working on this before anyone thought it was possible.”
Montana is well familiar with the problems in American health care. In a state known for its ranches and mines, health care is the largest industry, and the proportion of uninsured residents, 16.4 percent, is somewhat higher than for the nation as a whole.
Mr. Baucus loves everything Montana. Mike Mansfield, the former Senate majority leader from Montana, is his hero, and a conference room in his office is a veritable Mansfield shrine.
Mr. Baucus, who was a lawyer before entering politics, said he chose a career in public service after having an “epiphany” in Africa while on a trip around the world during a break from college. Earlier this year, Mr. Baucus and his second wife, Wanda, divorced after 25 years of what a joint statement called “spirited marriage.” From his first marriage, he has a son, Zeno, who is a lawyer in Washington.
In the interview, Mr. Baucus said he has tried to keep everyone at the table — a tactic he honed discussing tax issues in Montana. “If you don’t like something, suspend judgment for 15 minutes and let’s find a way to get to yes,” Mr. Baucus said.
He conceded that it was a mistake to rule out a fully government-run health system, or a “single-payer plan,” not because he supports it but because doing so alienated a large, vocal constituency and left Mr. Obama’s proposal of a public health plan to compete with private insurers as the most liberal position.
In more than a year of preparation, Mr. Baucus largely developed a new model for writing complex legislation, bringing in an array of interest groups, lobbyists and other experts to lay out issues and options for senators and aides.
He laid down his marker after the November election, releasing a 98-page white paper on reshaping health care.
Peter R. Orszag, the White House budget director, said that when he testified before the Finance Committee in his years as director of the Congressional Budget Office, Mr. Baucus was intent on identifying solutions.
“He would press me, and he would press other witnesses,” Mr. Orszag said. “ ‘O.K., fine. What should we do?’ ”
Mr. Orszag, who has agonized over health care costs for years, noted the Montana senator’s penchant for pain. “I am struck,” Mr. Orszag said, “by how he describes this as fun.”
Robert Pear contributed reporting.