Republican leaders barely scaled a key procedural hurdle to bring up the bill, but Democrats delayed its consideration and it was unclear whether the G.O.P. had the votes to pass it.
The Senate on Saturday narrowly voted to begin debate on the sprawling domestic policy package carrying President Trump’s agenda, clearing a key procedural hurdle after Republican leaders cut a series of deals with holdouts in hopes of winning the votes to pass it.
The vote to take up the bill was 51 to 49, after party leaders held the vote open for more than three hours in a suspenseful scene while they haggled with holdouts, both on the Senate floor and behind closed doors, to secure their support.
Two Republicans, Senators Thom Tillis of North Carolina and Rand Paul of Kentucky, voted with Democrats to block consideration of the measure.
Even as the vote unfolded on Saturday night, a clutch of hard-right Republicans, including Senators Ron Johnson of Wisconsin, Mike Lee of Utah, Rick Scott of Florida and Cynthia Lummis of Wyoming, were demanding that G.O.P. leaders insert even deeper spending cuts into the bill in exchange for their support. Ultimately, they all voted in favor, with Mr. Johnson switching his vote from “no” to “yes” in the final moments.
It was still not clear whether G.O.P. leaders had enough support to pass the measure and send it to the House for final approval in time to meet the July 4 deadline Mr. Trump has set. Democrats demanded a line-by-line reading of the bill, a procedural protest that was expected to take more than a dozen hours and likely push any final action in the Senate into Monday at the earliest.
But the test vote on Saturday night put the measure on track, even as it reflected the considerable angst among Republicans about their party’s signature bill.
