Chuck Schumer Has Found a Way to Get It Done. So Far.

Senator Chuck Schumer of New York ducked into the Democratic cloakroom on Tuesday to take a call on his old-school flip phone from President Biden. Senators were basking in a rare bipartisan success on infrastructure and gearing up for a more partisan budget brawl — and the president wanted to tell the majority leader he was a “magician.”

“Not yet, Mr. President,” Mr. Schumer objected from one of the private sanctuary’s phone booths, according to an official familiar with the call. “Only one ear of the rabbit is out of the hat.”

Mr. Schumer, barely eight months into his first year at the Senate’s helm, has steered both the $1 trillion infrastructure deal and the $3.5 trillion budget blueprint essential for the president’s ambitious policy agenda through the usually gridlocked Senate.

But he was acknowledging reality. He hit his interim legislative goals on the budget and infrastructure measures this week, despite widespread skepticism he could do so on such a tight schedule, but the most difficult work lies ahead.

Mr. Schumer is trying to deliver this fall perhaps the most significant government investments in public works and the social safety net since the days when Lyndon B. Johnson, whose portrait hangs in his Capitol office, ran the Senate and served as president. He has zero margin for error and must simultaneously advance legislation to fund the government after Sept. 30 and secure an increase in the federal government’s legal borrowing limit.

Saddled with a 50-to-50 Senate that Democrats control only through Vice President Kamala Harris’s tiebreaking vote, disaster is always just one defecting Democratic senator away.

But Mr. Schumer said he believed Democrats would eventually unite behind a “transformational” social policy bill, despite glaring disagreements on cost, because their experience over the past eight months — including passing a $1.9 trillion coronavirus stimulus package — had shown them that unity was their best legislative weapon.

“I think every single person believes that if we don’t come together, nothing is worse than whatever we are going to get,” Mr. Schumer said in an interview.

Given the evenly divided chamber and the outsize ambitions of Mr. Biden and his own members, Mr. Schumer has had to navigate treacherous political terrain. More moderate Democrats and the president have demanded that he demonstrate some semblance of bipartisanship, while more liberal members have clamored for government intervention to a degree no Republican would support.

His solution was the now familiar “two-track” strategy where he allowed the seekers of bipartisanship to go their own way on the infrastructure bill while the progressives could pursue their social policy agenda through a budget bill that would be protected from a Republican filibuster. It seemed counterintuitive that the tracks could coexist, but Mr. Schumer said both factions came to the realization that the strategy served their interests.

“There was a sort of equipoise to make it happen,” he said.

To move things along, Mr. Schumer applied the chief tool at hand for a Senate leader: control of the floor. At selected moments, Mr. Schumer strategically scheduled votes to force the issue, most notably when he set a crucial vote on the infrastructure legislation even though Republicans said they were not ready and the bill was not yet written.

Extremely wary of Mr. Schumer, who has tried to unseat many of them, Republicans suspected he was trying to blow up the deal, and the effort to bring the infrastructure debate to an early conclusion failed. But Mr. Schumer saw the exercise as a success even though, he said, “Republicans howled about it.” He said even key Republican negotiators conceded to him later that had he not acted, a final deal would not have emerged so quickly.

Republicans credited Mr. Schumer with not smothering the infrastructure talks and allowing about two dozen votes on amendments to the bill. It was a sharp break with recent Senate practice when such votes have been almost nonexistent as leaders sought to limit the political exposure of their members.

“I don’t think you can complain too much about the process,” said Senator John Thune of South Dakota, the No. 2 Senate Republican who ultimately voted against the bill.

“The follow-on now with this partisan bill is going to be a real fight,” Mr. Thune said. “They did not have to do it this way. They chose to, and our members are really dug in.”

“All it takes is one Democrat,” he continued. “If there is one thoughtful Democrat who objects to this, they could derail it or at least they could shape it to make it a lot less worse.”

Senator Rick Scott, the Florida Republican who is leading his party’s effort to recapture the Senate majority next year, said Mr. Schumer was making a politically lethal mistake stepping into what he called a taxing and spending bonanza that would fire up conservative voters and alienate moderate ones.

“He’s been good for me,” Mr. Scott said of Mr. Schumer. “He’s been good if you want to elect a Republican majority.”

Mr. Schumer thinks he may emerge with the upper hand. In addition to delivering key policy wins to the party’s base, he said the Democrats could prove to Americans that government could benefit them. That may well snuff out what he called a “sourness” in the public psyche that led to the election of former President Donald J. Trump.

“The way to do that is restore the American dream and give middle-class Americans hope for the future,” Mr. Schumer told reporters Wednesday.

Despite his success on the public works and the budget front, Mr. Schumer has not managed to break free one of the party’s top policy priorities — a far-reaching voting rights measure that many Democrats see as crucial to offsetting voting restrictions imposed by Republican legislatures. Absent a federal response, Democrats fear they may lose their majorities next year because of ballot restrictions and partisan gerrymandering, regardless of their legislative accomplishments.

Mr. Schumer has managed to rally all 50 Democrats behind assembling a slimmed-down version of a voting measure, but Republicans again blocked his effort early Wednesday to debate the legislation. Some activists have suggested Mr. Schumer is not moving aggressively enough to try to change Senate rules to overturn the filibuster, which Republicans have used to block the measures. But at least two Democrats — Senators Joe Manchin III of West Virginia and Kyrsten Sinema of Arizona — have said they would not join in such an effort, depriving Mr. Schumer of the votes to do so.

Senator Debbie Stabenow of Michigan, one of Mr. Schumer’s top deputies, said he was doing everything he could on voting rights.

“From the outside, people can say, ‘Well, the president or Chuck Schumer should just make them,’’’ she said of the holdouts on the filibuster. “But the reality is, every member is elected on their own, and they have a right to cast their vote and be held accountable as they see fit.”

Mr. Schumer said voting rights will be a priority when the Senate returns in September and that if Democrats, including Mr. Manchin and Ms. Sinema, see continuing Republican intransigence, “then we will see what happens.”

With the initial vote on the budget plan behind him, Mr. Schumer has set a Sept. 15 deadline for the Democratic chairmen of the Senate committees to produce the fine points of the multitrillion-dollar budget plan. That will set off the fight with Republicans — and among Democrats — in earnest. It will then be up to Mr. Schumer to see if he can pull the remainder of the rabbit out of the hat.

“It is hard, and nothing is a done deal,” he said. “And this is the hardest yet.”