Democrats excoriated the measure on the Senate floor. “Historically low teen pregnancy rates did not happen in a vacuum,” said Senator Gary Peters, Democrat of Michigan. The measure, he said, “will disproportionately hurt people in rural and underserved areas where these clinics are more often than not their primary source of health care.”

Mr. Pence was also forced to travel to the Capitol earlier in the day for a procedural vote that opened debate on the bill.

The final vote remained open for more than an hour as aides waited for Mr. Isakson. He finally arrived in a wheelchair and was transferred to a walker so he could make his way into the Senate chamber and, flanked by Senate pages, give a thumbs up as an “aye.” Mr. Pence then swept in to break the tie.

A handful of Democrats stood on the floor, taking in the scene. “It will take one Republican this afternoon on the final vote to say yes for the women in their state,” said Senator Patty Murray, Democrat of Washington. “That’s all we’re asking. For the women of this country.”

The Democrats could find no other Republicans to join them. But Republicans were also scarce in defending the bill on the floor before it passed.

“The deafening silence from the group of almost entirely male Republican senators are voting today to make it harder for women to get health care they need,” Ms. Murray said. “Not one spoke today to justify this vote.

“Where were those Republican senators today, Mr. President?” she added. “Why did they feel so entitled, not just to interfere with women’s health care decisions, but to do so without explaining themselves? If they are ashamed of their votes today, which they should be, they had ample opportunity to reconsider.”