WASHINGTON — This is why Sen. Pat Toomey came to Washington.

With the final passage of his party's tax bill Wednesday, the Pennsylvania Republican scored a landmark personal achievement — sharply cutting taxes in the aim of spurring economic growth, a goal that has driven his work in public life.

"This is a very big deal for me," Toomey said in his Senate office Wednesday morning, wearing a crisp blue suit and pink tie. "I've wanted to do this for 20 years, and I'm really grateful to have this opportunity. This comes along less than once a generation."

Toomey had a front-line role on the controversial plan, helping to write it, sell it in public, and defend it on the Senate floor. It was the culmination of work he has pursued since joining the House in 1999, in leading the conservative Club for Growth, and in his seven years in the Senate.

President Trump called out Toomey at a White House celebration, saying, "He knows his business."

A former derivatives trader and owner of a small chain of sports bars near Allentown, Toomey made regular trips to White House talks and was one of four GOP senators charged with explaining the bill to colleagues at lunch meetings. When the first Senate version passed earlier this month, Toomey spent hours on the chamber's floor, papers stacked on his desk as he jousted with Bernie Sanders, Pennsylvania's Bob Casey, and numerous other Democrats who arrived to criticize it.

At one point, Sen. Cory Gardner (R., Colo.) walked up to Toomey and silently pumped his fist in encouragement.

Toomey has long been one of the GOP's most prominent voices on fiscal policy, pairing staunchly conservative views — often to the right of fellow Republicans — with wonky details boiled down to digestible talking points and a mild demeanor that belies his firm viewpoints.

"I don't think this would have happened without Pat Toomey," Gardner said. "He is somebody who has a keen intellectual grasp of the issues, but can explain it in a very common-sense way."

Toomey also had a leading role this year in trying to repeal the Affordable Care Act, pushing hard to roll back Medicaid funding. He pressed to make the tax cuts as large as possible, despite projections that they could explode the deficit.

The measure Toomey helped craft, however, is deeply unpopular, according to multiple public opinion polls, and the overwhelming consensus among nonpartisan analysts is that its largest benefits will go to the wealthy and businesses.

"It makes sense that the senator from Wall Street is doing everything that he can to pass this bill," said Marc Stier, executive director of the liberal Pennsylvania Budget and Policy Center. "It makes no sense that the senator from Pennsylvania is doing so."

Toomey said the bill would provide benefits across the income scale and would more than pay for itself by stirring new economic energy.

"The vast majority of working and middle-income individuals and families get a direct tax cut," he said.

On the face of it, Toomey's fervent advocacy of the tax bill contradicted another core element of his fiscal philosophy — opposition to deficits. Nearly every recent nonpartisan analysis predicts the tax bill will increase deficits. So do staunch deficit hawks, and a wide array of top economists.

The Penn Wharton Budget Model, for example, predicted $1.9 trillion to $2.2 trillion in new debts, even while accounting for economic growth. Most other analyses projected at least $1 trillion in added debt.

Toomey has opposed spending bills for much less. He voted last year, for example, against plans to spend $600 million on opioid treatment, citing the red ink.

On this measure, however, he negotiated a critical GOP deal to allow for $1.5 trillion in new debt to fund the plan and, according to the Washington Post, floated the idea of an even bigger cut to stake out a stronger negotiating position.

Toomey predicted a stronger economic boost than many analysts expect, saying 0.2 to 0.4 percent of growth above existing projections over the next decade would be enough to pay for the cuts and possibly cut the deficit.

"You have to be very pessimistic about America's future to think that we can't achieve that, and I am not pessimistic about America's future," he said.

Some Republicans are eyeing another long-standing aim for fiscal conservatives like Toomey: scaling back spending on Social Security, Medicare, and Medicaid. Toomey has long argued that they are growing too fast and must be reined in to be viable for future generations.

Democrats are ready to pounce if that happens, noting that Republicans have just undercut federal revenues. Toomey said it's about spending.

"You can't tax your way to a solution," he said.