WASHINGTON (Reuters) - A broad healthcare overhaul emerged unscathed on Friday from the first week of Senate committee debate, with Chairman Max Baucus keeping fellow Democrats in line and shielding key elements from Republican attacks.

Senator Max Baucus (D-MT) chairman of the Senate Finance Committee, discusses the healthcare reform bill during a news conference on Capitol Hill in Washington, September 16, 2009. REUTERS/Hyungwon Kang

Four days of sometimes contentious battle in the Democratic-controlled Senate Finance Committee left the main tenets of Baucus’s bill untouched and gave reform advocates hope that Republican Senator Olympia Snowe would back the final version.

Snowe, a member of the bipartisan “Gang of Six” negotiators who failed to reach agreement on the plan before the panel’s debate, was the only Republican to cross over and side with Democrats on several votes during the week.

Her support would be a big step toward winning approval in the full 100-member Senate, where Democrats have little margin for error with a 60-vote majority -- exactly the number needed to clear Republican procedural hurdles.

“The battle lines are taking shape,” said Len Nichols, director of the health policy program at the New America Foundation. “The Democrats appear very disciplined, and it’s pretty clear that Snowe might still support this thing -- which is what they need.”

Baucus’s proposal, one of five healthcare bills pending in Congress, closely mirrors President Barack Obama’s plans to rein in costs, tighten regulations on insurers and expand coverage to many of the 46 million uninsured people living in the United States.

Baucus won every key fight during the first week of debate. He protected the White House’s $80 billion deal with drugmakers and kept Democrats together to preserve an individual requirement to buy insurance and reject Republican efforts to block some cuts in the Medicare insurance program for seniors.

Baucus had brought his fellow Democrats on board before the debate by incorporating into the bill a package of Democratic amendments aimed at making insurance reforms more affordable for workers.

Snowe crossed party lines to support Baucus on the vote on the individual insurance mandate and on other votes, but the other Republican “Gang of Six” negotiators -- Charles Grassley and Mike Enzi -- stayed in the Republican camp.

IN SEARCH OF A BREAKTHROUGH

“They need a breakthrough moment where they find some middle ground, and I still think at the end of the day they will find it,” Bob Blendon, a health policy and political analyst at Harvard University, said of lawmakers working on healthcare.

“There is no reason for people who are going to move over and compromise to do it early,” Blendon said. “You have your maximum advantage by taking your time. The people who are going to compromise haven’t done it yet.”

The Senate panel renews debate on Tuesday with a battle over Democratic amendments to add a government-run “public” insurance option in the bill -- the only one of the five pending healthcare measures in Congress without it.

The public option is favored by Obama as a way to create competition and lower insurance costs, but critics say it could undermine the private insurance industry.

Democratic Senators Charles Schumer and John Rockefeller, who will bring up the public option in committee, say it may have a hard time passing the more conservative Senate Finance panel but will have stronger backing in the full Senate and House of Representatives.

“The committee is what starts the debate and gets people thinking,” Schumer told reporters. “As the process moves on, for the public option and for some other things, it gets better and better.”

In the House, where Speaker Nancy Pelosi has promised a final bill will include a public option, Democratic leaders met on Friday to work on blending the chamber’s three pending bills into one measure for floor action.

They said they were making progress on trimming the total cost to $900 billion -- all three bills were at $1 trillion or more.

“We are narrowing the number of issues we have to deal with,” House Speaker Nancy Pelosi told reporters. She said they were looking at proposals in the two Senate committees, including a tax on high-cost insurance policies included in the Finance bill.

She said no decisions had been reached and the group would meet again next week.