Bipartisan Deal on Health Care Issues Hits a Snag Among Senate Democrats

The deal is as politically remarkable as it is substantive: a long-term plan to finance health care for older Americans, pay doctors who accept Medicare and extend popular health care programs for children and the poor. It was cobbled together by none other than House Speaker John A. Boehner and Representative Nancy Pelosi, the leader of House Democrats, who rarely agree on anything, with the apparent blessing of a majority of their respective members.

Then along came a surprising impediment: Senator Harry Reid of Nevada, the minority leader, along with other Senate Democrats, objected toabortion restrictions in the bill and limits to an extension of a health insurance program for children. They have begun to undermine what was poised to be a sweeping bipartisan solution to several policy problems that have long vexed Congress.

It is a role in which Mr. Reid is becoming increasingly comfortable as he exploits his leverage in the minority to thwart his political opponents, even if that means an unusual split with Ms. Pelosi.

The House is expected to vote on the plan Thursday, but its fate in the Senate is unclear. The disagreements over the bill — aired in an unusually open fashion among leaders of the same party — were surprising and unsettling for Ms. Pelosi, whose staff members were privately questioning Mr. Reid’s strategy.

“This is what we could get done in the House,” Ms. Pelosi said on Tuesday. “I’m very proud of the product.”

While Senator Mitch McConnell of Kentucky, the majority leader, could possibly muster enough votes from his own party and Democrats to drag a House-passed bill to passage, the conflict reflects a new dynamic in Congress, in which Senate Democrats are assuming the role played for years by House Republicans — waging an ideological fight from a disadvantaged position — and Republicans are eager to prove themselves good stewards of government.

At the same time, the debate over abortion is increasingly surfacing in legislative battles. Abortion rights supporters, concerned about a provision in the House bill, say they are continuing to lose ground in Congress with measures that seek to trim away at access. “We are trying to change that history, and we keep losing,” said Senator Dianne Feinstein, Democrat of California, on the floor of the Senate last week, when a bill to aid victims of sexual trafficking stalled over another abortion component.