"I hope they [Republicans] will back off and say, 'You know what, we have reflected on this … and we have decided to come off this crazy idea,' " said Boxer, referring to Republicans' demands to to remove funding for all of Title X. 

Last year, $75 million of Title X funding went to Planned Parenthood affiliates, which Republicans object to. Planned Parenthood provides abortion services but can't use federal money for them. Republicans argue there's no real way to segregate the private dollars dedicated to abortion services and the federal dollars backing other areas of care.

Democrats argue the Republicans are holding up negotiations because of disagreements on funding for policy issues. Republicans claim the holdup is over how much to cut in spending.

If a deal to fund the government is not struck before midnight Friday, the government will shut down. House Republicans and Senate Democrats remain in negotiations.