"If it isn't clear that government money is not to be used to fund abortions -- whether it's subsidies or direct payments or tax credits or something like that -- I will not support it," said Sen. Ben Nelson of Nebraska, long seen as a swing vote on the Democrats' health-care legislation. "If it doesn't make it clear that it does not pay for abortion, you can be sure I will vote against it."
Leading Senate Democrats are seeking to prevent the abortion issue, which almost capsized the health-care debate in the House, from engulfing the Senate.
Mr. Nelson and Sen. Robert Casey of Pennsylvania are the two strongest abortion foes among Senate Democrats. They've talked about how to ensure that taxpayer-funded abortions aren't allowed by the legislation.
Senate Democrats need 60 votes to overcome an expected filibuster, and all 40 Republicans are likely to oppose the bill. So the votes of Messrs. Casey and Nelson -- as well as those of every other Democrat and independent -- are required for passage. Abortion hasn't been a big issue in Senate health talks so far. But Democratic leaders expect that to change after its eruption among House Democrats over the weekend.
House Speaker Nancy Pelosi (D., Calif.) capitulated at the 11th hour to Rep. Bart Stupak (D., Mich.), who led a group of antiabortion Democrats. Mr. Stupak introduced an amendment blocking the bill's government-administered insurance plan from covering abortion and forbidding people who receive government subsidies from buying policies covering abortion through a new insurance exchange.
President Barack Obama, asked in an ABC News interview whether the Stupak language met his test for preserving the status quo on abortion, said, "There needs to be some more work."
The focus is now on Senate Majority Leader Harry Reid (D., Nev.), who is responsible for crafting a health-care bill to bring to the Senate floor. Reid spokesman Jim Manley said the senator was considering the abortion language. "It's something he will have to talk to members of his caucus about," Mr. Manley said.
Mr. Reid opposes abortion and faces re-election next year in a conservative state. He is often in a delicate position over the issue, since he leads a Democratic caucus that strongly supports abortion rights.
Before Mr. Stupak's amendment was adopted, House and Senate bills required insurers to segregate public subsidies from private premiums, and use only the latter to cover abortion. Abortion-rights supporters say that would guarantee taxpayer funds aren't used for abortion. But abortion foes, such as Mr. Nelson, disagree.
The Congressional Budget Office is expected to release its cost estimate for Mr. Reid's bill this week. That could clear the way for the Senate to begin debate -- but exactly when isn't clear. Mr. Reid said he wanted to bring it to the floor as soon as possible.
If Mr. Reid doesn't include the Stupak language in his bill, proponents are all but certain to offer it as an amendment.
Both sides in the abortion debate have begun pressuring senators to vote their way. Abortion-rights advocates argue that opposition will grow as people understand the reach of Mr. Stupak's measure. "We're going to hold the Senate accountable and hold their feet to the fire," said Nancy Keenan, president of NARAL Pro-Choice America. "We are reaching out to every single United States senator on this issue."
On the other side, the U.S. Conference of Catholic Bishops -- which was instrumental in forcing the change in the House bill -- sent a message to churches Saturday, urging members to ask their senators to "correct the serious defects in their bills" by tightening insurance coverage for abortions.
Sen. Barbara Boxer (D., Calif.), said she believes a compromise can be reached short of the Stupak language. "I'm confident we can have the votes here for a far less radical amendment."