WASHINGTON — Senate Republicans were forced to call on Vice President Mike Pence to pass an anti-abortion measure Thursday, marking the second time they’ve cast a help line to the new administration to move legislation.

Pence delivered the tiebreaking vote on a resolution reversing an Obama administration rule that prevented states from withholding family-planning dollars from Planned Parenthood and other clinics that provide abortions. The vice president’s appearance in the Senate chamber was needed after two Republicans, Sens. Susan Collins of Maine and Lisa Murkowski of Alaska, defected. No Democrats supported the resolution.

The measure, a priority for groups that oppose abortion, would allow Tennessee and other conservative states to resume policies blocking Planned Parenthood clinics from getting federal funding through the Title X family-planning program. Those dollars can’t be used for abortions, but conservatives feel abortion providers shouldn’t receive any taxpayer funds.

While courts have not allowed states to withhold Medicaid money from Planned Parenthood, they’ve generally allowed states to redirect family-planning dollars to other health providers.

“It’s a simple statement of where we used to be,” said Sen. James Lankford, R-Okla. “States could choose to have Planned Parenthood as part of their Title X funding states should not be compelled to.”

The women’s health organization dodged a bullet last week when a House bill repealing parts of the Affordable Care Act and blocking Planned Parenthood’s Medicaid funding was pulled amid a rebellion of conservative and moderate Republicans. But it remains a key target for conservatives.

President Donald Trump is expected to sign the Title X measure, which the House approved in February, though his administration has yet to release a statement of intent on it.

Sen. Patty Murray, D-Wash., said Thursday she is apprehensive that Republicans will continue trying to strip streams of federal dollars from Planned Parenthood this year through other means, including by attaching riders to a spending bill. The money Planned Parenthood receives through Medicaid cannot be used for abortions.

“We should all be aware there is more headed our way,” Murray said on the Senate floor. “We are going to fight these efforts every step of the way.”

Conservative activists, who saw in the ACA repeal bill their first realistic chance to block Medicaid from reimbursing any services at Planned Parenthood clinics, are urging Congress to pass a defunding measure before it breaks for an April recess.

“You have a clear path to accomplish this goal,” several dozen groups, including Susan B. Anthony List, March for Life and Family Research Council, wrote in a letter being sent to members Friday. “There are no excuses for inaction.”

The Title X bill is a small but significant victory for abortion opponents. Thirteen states have blocked Planned Parenthood and other abortion providers from getting the family planning dollars, which can be used for services such as contraception and screening for sexually transmitted diseases.

But even this legislation was perilously close to defeat. West Virginia Sen. Joe Manchin, the Democrat most likely to support it, instead sided with his party. That meant Republicans had to bring in not only Pence, but also Sen. Johnny Isakson, R-Ga., who has been absent for several weeks recovering from two back surgeries.

In both a procedural vote in the morning as well as the final afternoon action, Isakson brought the measure to a 50-to-50 tie, and Pence cast his vote for its final passage.

Isakson said he had always planned to ease back into his routine this week by flying up from Atlanta, where he is undergoing a 12-week rehabilitation, to cast some votes. “I have watched the Congress of the United States on television for eight weeks trying to rehab from spinal surgery — I know more about it than I knew about it when I was here,” Isakson joked.

Pence’s first tiebreaker came Feb. 7, when he cast the deciding vote to confirm Betsy DeVos as education secretary.

The last time a vice president had to break a tie on final passage of legislation was nearly a dozen years ago, when Dick Cheney voted for the Deficit Reduction Act of 2005.

Cheney broke eight ties as vice president, mostly to pass amendments or advance legislation on procedural votes. Joe Biden never had to break a tie during his eight years as vice president. Al Gore broke four ties, all on legislation or procedural matters.