House Democrats plan to vote Friday on a sprawling, more than $2 trillion package to overhaul the country’s health care, education, climate, immigration and tax laws, pushing back their initial plans after Republicans mobilized to briefly obstruct a central piece of President Biden’s economic agenda.

Democrats began Thursday hoping to hold a swift vote on the signature spending initiative, putting an end to months of intense, internal wrangling among their own liberal and moderate ranks. The bill’s passage would have notched another major milestone for Biden just days after he signed into law a separate effort to invest $1.2 trillion in the nation’s infrastructure.

But their timetable hit an unexpected snag after House Minority Leader Kevin McCarthy (R-Calif.) took to the chamber floor beginning in the evening. He soon embarked on a form of filibuster, using the unlimited time available to House leaders ahead of votes to rail on the roughly $2 trillion bill. McCarthy’s winding speech attacked Democrats over a broad range of issues, including border security and Afghanistan policy, and repeatedly mischaracterized their exact spending ambitions.

The GOP leader’s ongoing remarks often drew jeers and laughs from Democrats, some of whom left as he spoke. But it ultimately had some effect, even if temporarily: Once the speech lapsed past midnight and into its fourth hour, Democratic leaders made the decision to hold off on a vote on the spending bill until later Friday.

“We’re going to recess, and we’ll come in at 8 a.m.” Friday, House Majority Leader Steny H. Hoyer (D-Md.) told reporters.

“He wants to do it in the middle of the night,” Hoyer said of McCarthy’s motivations for speaking for so late. “We’re going to do it in the light of day.”

Back on the House floor, meanwhile, McCarthy sounded an even more emboldened note. “I don’t know if they think because they left I’m going to stop,” he said. “I’m not.”

McCarthy’s fiery, lengthy rebuttal marked a temporary setback on a day when Democrats mostly found reason to rejoice. Earlier in the evening, the Congressional Budget Office concluded its fiscal analysis of the package, satisfying moderate Democrats, who had demanded the data to assess whether their party’s more than $2 trillion in new initiatives are financed in full.

The CBO analysis found that the bill would result in a net increase in the deficit totaling $367 billion over the next decade. But the estimate did not include the full savings that could be achieved from some of the Democrats’ revenue-raising provisions, including a plan to empower the Internal Revenue Service to recapture unpaid federal taxes. The White House has said that IRS enforcement alone could capture roughly $400 billion in additional revenue.

With that amount factored into the final estimate, Treasury Secretary Janet L. Yellen said in a statement Thursday evening that the legislation, known as the Build Back Better Act, “is fully paid for,” adding that over time it would help reduce the deficit as a result of tax policies that “ask the wealthiest Americans and large corporations to pay their fair share.”

Top White House aides later briefed moderates on Capitol Hill to further make the case that the package would not add to the deficit. Shortly after exiting the gathering, Rep. Stephanie Murphy of Florida, one of the leaders of the centrist-leaning Blue Dog Coalition, said in a statement she intended to vote for the bill despite some additional “reservations about the overall size of the legislation.”

“I think we were all united around the desire to have complete information,” Murphy later told reporters.

Rep. Josh Gottheimer (D-N.J.), another party centrist, similarly expressed optimism about the package as he told reporters he continued to review the spending data.

President Biden is hitting the road to tout the passage of the infrastructure bill, hoping he can reverse his flagging poll numbers before the 2022 midterms. (Joyce Koh/The Washington Post)

The late statements of support provided a fresh jolt of good news for Democrats who had struggled for months to advance Biden’s broader economic policy agenda. “At the close of the debate, all that remains is to take up the vote — so that we can pass this legislation and achieve President Biden’s vision to build back better,” House Speaker Nancy Pelosi (D-Calif.) told members of her caucus earlier Thursday evening.

The roughly $2 trillion measure is vast in its scope: It aims to expand Medicare to include new hearing benefits, lower the cost of some prescription drugs for millions of seniors, provide free prekindergarten for all American children and invest new sums to combat climate change. It proposes a slew of new aid to help low-income families in greatest need, and it covers its spending through new taxes targeting millionaires as well as corporations that currently pay nothing in federal taxes.

Opening debate earlier Thursday in the House, top Democrats took to the floor to stress the popularity of the president’s vast spending agenda.

“Virtually every poll on this piece of legislation has shown overwhelming support for each of the elements we are proposing,” said Rep. John Yarmuth (D-Ky.), chairman of the chamber’s Budget Committee, which helped craft the legislation.

Republicans, meanwhile, blasted the package, labeling it as socialism and arguing it would contribute to an existing trend of rising prices by flooding the economy with more money. Democrats contend their measure would combat inflation, aiding Americans who are struggling financially. But Rep. Jason T. Smith (R-Mo.), the top GOP lawmaker on the budget panel, at one point during debate shot back: “The American people aren’t that stupid.”

Shepherding the proposal to passage has been an uphill battle for Pelosi, who has only a three-vote advantage in the House — and a fractious caucus to keep intact. Moderates and liberals at times have warred over its spending initiatives, forcing Democrats to scale back their initial package, valued at $3.5 trillion, in dramatic fashion.

But Pelosi, Biden and other Democratic leaders helped broker an end to the stalemate over a week of tense negotiations. By Thursday morning, the developments left Pelosi ebullient that the House was on the verge of clinching a “spectacular vision for the future,” adding: “It will create millions of good-paying jobs, lower families’ costs and cut their taxes, while making the wealthiest few and big corporations pay their fair share.”

Even as Democrats unified in support of the package, Republicans readied an onslaught of opposition — led by McCarthy, whose winding speech attacked Biden and slammed Democrats for border security.

“Why don’t we pass a bill to honor our Border Patrol agents?” McCarthy mused at one point as the speech approached the start of its third hour. “You know what you’re spending money on? Not to build the wall!”

At various turns, he referenced at length or in brief the Hallmark television channel, China’s supersonic missile capabilities, the famous painting of George Washington crossing the Delaware River, his friendship with Elon Musk and his recent coronavirus vaccine booster, which he said had left him with a headache. McCarthy could speak for such length as a result of what are known as “magic minutes” in the House, which essentially afford party leaders the privilege to speak as long as they would like. Pelosi herself had used the same tactic in 2018, speaking for eight hours at the time in defense of young immigrants known as Dreamers.

Eventually, though, a successful House vote on the spending package would send the bill next to the Senate, where the chamber’s majority leader, Sen. Charles E. Schumer (D-N.Y.), has said he hopes to conclude consideration of the bill before Christmas. Lawmakers including Sen. Joe Manchin III (D-W.Va.) continue to harbor concerns about the size and scope of the bill.

Other troubles also remain, including a fight among Democrats over a provision to address state and local taxes. The House bill would raise the amount that Americans can deduct on their yearly federal returns, a plan that chiefly aids families who live in high-cost states such as New York and California. But some liberals say the policy is too generous, largely benefiting wealthy Americans, in a break with the spirit of the bill.

The dispute drew in the White House on Thursday, when press secretary Jen Psaki acknowledged some of the concerns with the proposal to boost state and local tax breaks, a provision known as SALT.

“It is a component that wasn’t initially proposed” by the White House, she said. “This is a part of compromise.”

Amid the squabbling, Democratic leaders on Thursday also maintained that the bill is fully financed — a contention that some cost-conscious centrists continued to evaluate Thursday night.

Experts so far have split over the exact cost of the package. Some estimates reflect it is $2.1 trillion, though others believe its cost is closer to $2.4 trillion if it includes the tax aid provided by lifting the SALT cap. Either way, it marks an uptick from the earlier $1.75 trillion blueprint that Biden helped broker with centrists in Congress, reflecting last-minute additions, including a proposal to provide paid leave to Americans.

Pegging the cost at $2.4 trillion, the Committee for a Responsible Federal Budget released an analysis Thursday that showed the bill could add to the deficit over 10 years, based on data furnished by the CBO. But the official congressional scorekeeper did not factor into its calculations the full amount of savings that the White House anticipates from the package. That includes a plan to empower the IRS to pursue unpaid taxes, which Democrats say the CBO has historically underestimated.

McCarthy latched on to the IRS provision as part of his lengthy speech Thursday night, alleging the agency would add thousands of officials to audit Americans. The White House previously has said the focus is on “stopping rich Americans from cheating on their tax bills.”