Despite more than 60 years in Congress between them, Charles E. Grassley, the Iowa Republican, and Max Baucus, the Montana Democrat, are outsiders -- loners whose independent streaks make colleagues wary, sometimes even mistrustful. But unlikely as it may seem, the partnership between these two slightly eccentric men may hold the key to overhauling the nation's sprawling health-care system -- a legislative grail that has eluded the giants of the Senate for more than half a century. In the face of strident criticism from colleagues in both parties, Baucus (who chairs the Senate Finance Committee) and Grassley (the panel's senior Republican) are laboring to fashion a series of compromises on health care that might win the support of a bipartisan majority on Capitol Hill. Their effort got a nod Wednesday from Senate Majority Leader Harry Reid, D-Nev., who at a meeting with Grassley encouraged the quest despite complaints from more-partisan Democrats. The stakes remain high. If Baucus and Grassley fail, this year's historic healthcare debate easily could devolve into another battle royal between the parties, with the prospects for meaningful legislation uncertain at best. Many Democrats and Republicans have already rejected a middle ground. 'On both sides, there are people who want it their way or the highway,' said Senate Budget Committee Chairman Kent Conrad, D-N.D., who is working with the two on a health-care bill. 'But if we want to really make a difference with health care ... it is critical that we find some compromise.' Baucus and Conrad are among the senior Democrats who believe their party will need Republican support to get the 60-vote supermajority necessary to prevent a GOP filibuster and move a major health-care bill to the president this year. Democratic Sens. Edward M. Kennedy of Massachusetts, who had been expected to lead the charge on health care, and Robert C. Byrd of West Virginia are battling serious illnesses and may not be able to cast their votes. Moreover, a number of moderates in the party have expressed reservations about parts of President Barack Obama's health-care agenda, including the creation of a government health insurance plan. And although Democrats could use a procedural rule they passed earlier this year to push through some health-care legislation with a simple majority, the rule may prevent them from enacting a comprehensive bill. Baucus and Grassley have been among the fiercest critics of a single-party approach. 'Fundamentally, legislation that is historic, that is comprehensive, that has a large number of senators supporting it is more durable,' Baucus said in an interview. 'It will be more sustainable and will inspire more public confidence.' Baucus, who came to the Senate in 1979, and Grassley, who joined two years later, have let that philosophy guide them since they assumed senior posts on the finance committee eight years ago. The two do not socialize outside of the Senate. But since 2001, they have met nearly every Tuesday evening at 5 p.m. in Baucus' conference room on the fifth floor of the Hart Senate office building. Slowly, both men said, they grew to trust one another and look for places where they could agree. 'We are pragmatists,' Grassley said while in Iowa recently to meet with constituents. 'We come from similar states, and I think we have a similar idea of what bipartisanship is all about.' Said Baucus: 'Most people in this country want us to basically work together, to get something done between the 20-yard lines. They are in the center.' Their bipartisanship has at times grated on their colleagues, however. Baucus infuriated fellow Democrats by working for President George W. Bush's tax cuts in 2001 and then featuring a photo of himself with Bush in a campaign flier during his 2002 re-election campaign. It was only last year that Baucus emerged as a leading champion of universal health care, a goal that Democrats have been chasing since the Great Depression. From the start, he enlisted Grassley's help. The two senators' staffs have been in almost daily contact, hashing out language for a bill that Baucus has promised will expand coverage, hold down costs and improve quality. Whereas Democrats on Kennedy's health committee developed their bill largely by themselves and then showed it to their GOP colleagues -- a process that irked Republicans -- aides to Baucus and Grassley 'started with a blank sheet of paper,' as one Republican staffer said. The effort has won implicit support from Obama, who has said repeatedly that he does not want to draw lines in the sand on health care. The president has spoken frequently with both senators in recent months. But as the health-care debate intensifies on Capitol Hill, it is unclear how long Grassley and Baucus can sustain their middle-of-the-road approach. (Optional add end) Grassley is under pressure to break off negotiations from GOP lawmakers -- including Arizona's Jon Kyl, the No. 2 Republican in the Senate, who said in a recent C-SPAN interview that the Iowa senator had no authority to represent Republicans. 'There are a significant number of senators, some in powerful positions, that feel I am helping to pass something that is going to be bad for this country,' Grassley said. 'They believe that if I wasn't working for a bipartisan thing, Democrats would implode and beg for Republican help.' The pressure on the other side of the ideological spectrum is even more intense, as liberal lawmakers and advocacy groups intensify their campaign for a government insurance plan, which polls show is broadly popular. In recent weeks, several groups, including Health Care for America Now and the Laborers' International Union of North America, have run ads targeting Grassley and Baucus in their home states. 'The majority of people support where Democrats want to take this country,' said Healthcare for America Now national campaign manager Richard Kirsch. 'If you have a majority of Democrats who want something, why should the minority define what will happen? That just seems like bipartisanship for bipartisanship's sake.' 