BETHLEHEM, Pa. — U.S. Sen. Pat Toomey announced Monday that he won’t run for reelection or governor in 2022, sending shockwaves through the Pennsylvania political establishment and depriving Republicans of their best-known candidate in the competitive elections that will follow this year’s presidential race.

Toomey said his decision, first reported Sunday by The Inquirer, was personal and not political. He noted that by the time his current term ends, he will have spent 18 of the previous 24 years in elected office, and said he wants to spend more time with his family. He said he would complete his Senate term, which will run through early 2023.

“Representing the people of Pennsylvania — this big, beautiful, complicated diverse state — has been an extraordinary, amazing honor, it still is, and it’s been by far the highlight of my professional life,” Toomey told reporters gathered in Bethlehem for his announcement.

“I’m looking forward to more time back at home," he said, later adding, “Eighteen years is a long period of time in a person’s life.”

Asked whether he thought he could have won another statewide race in 2022, Toomey noted his record of success in several tough House and Senate elections. “I think if I decided to run, I would have, I would have won again,” he said.

He would have faced stiff opposition, however: Progressive activists have made Toomey a top target since 2016, and were gearing up to block him in his next election. Even so, Republicans were ready to support him, and his departure takes Pennsylvania’s most prominent sitting Republican out of the mix, raising questions about who will represent the party on the ballot in 2022 and opening opportunities for Democrats eyeing the governor’s office and a swing Senate seat.

Toomey’s decision leaves Pennsylvania Republicans without a favorite in key 2022 contests, likely leading to sprawling primaries for governor and Senate, while boosting Democratic hopes in both races. Pennsylvania’s Senate seat is expected to be one of a few that determines control of the chamber.

For now, Toomey, 58, reaffirmed his support Monday for President Donald Trump’s reelection, and for his party’s push to confirm Trump’s nomination of Judge Amy Coney Barrett to the Supreme Court before Election Day.

And although he plans to leave public life after he leaves office, he said he is “cautiously optimistic” that Republicans will hold the Senate in the Nov. 3 election, and that he will become chairman of the Senate banking committee. Toomey, a former Wall Street banker, talked about several conservative initiatives he hopes he can push through if that happens.

Toomey’s surprise announcement came at an already tumultuous moment for Republicans in Washington. Trump had been hospitalized with the coronavirus. Three GOP senators have also contracted the virus, which could hamper the party’s push to confirm Barrett. And Trump and fellow Republicans face increasingly dire poll numbers, threatening their hold on both the White House and Senate.

Toomey, who rose to the Senate during the 2010 Tea Party wave, chased then-Sen. Arlen Specter out of the GOP with a challenge from the right. He was a staunch conservative on most policy questions, with a particular focus on fiscal issues. But while pulling his party rightward on issues such as tax cuts and the Affordable Care Act, Toomey largely avoided culture wars and presented himself as a mild-mannered Republican willing to compromise on certain issues, including gun laws. That helped him eke out statewide victories with support from moderate voters.

Toomey was widely expected to run for governor and to be the GOP front-runner for that position. Instead, his decision to pass has thrown open both the 2022 gubernatorial and Senate races, inviting a slew of people in both parties to evaluate their chances.

The timing was surprising: Most political insiders expected Toomey to wait to see the results of the 2020 election and the political landscape before announcing his choice. But he said that people had been offering to help his next campaign, and that he wanted to be honest with them.

“Once I reached the decision, I need to be candid with them, and I feel like I should be candid with everybody,” Toomey said. “I made a decision, it’s not going to change, so I want to let everybody know.”

Toomey spoke in the studio of PBS39, a public television affiliate with hallways adorned with Sesame Street memorabilia. His wife and three children stood behind him, all wearing face masks.

Pressed repeatedly on the timing of the announcement, Toomey said he made the decision recently and that Trump’s COVID-19 diagnosis played “absolutely no role whatsoever.” He said that his family had made “a lot of unseen sacrifices over the years” that allowed him to pursue a life of public service, and that he looked forward to more time at home.

Asked whether disagreements with Trump were a factor, Toomey said they have a constructive working relationship.

“I decided early on I’m not responsible for the president’s Twitter feeds,” he said. “I am not responsible for editing his comments in any given medium. I work with this president on a regular basis. ... And when I’ve disagreed with him, which I have, I haven’t been bashful about saying so. But that has nothing to do with this decision.”

Many expected Toomey to leave the Senate after his term ends. He supports term limits and had previously suggested he was unlikely to run again. But his decision to pass on the governor’s race, too, stunned political insiders

Toomey’s time in elected office began with a U.S. House stint from 1999 to 2005, followed by a Senate term that began in 2011. In between, he was still in public life, he noted Monday, leading the conservative free-market group the Club for Growth and running for the Senate in 2010, after his 2004 bid fell just short in the Republican primary. At the Club for Growth he targeted so-called RINOS, Republicans in Name Only, for being insufficiently conservative. But he later sought to reach out to swing voters by pitching himself as “an independent voice.”

He won heavyweight Senate races in 2010 and 2016, though narrowly. He expressed confidence he could do it again, but might have faced a far different political landscape in 2022.

Since 2016, progressive activists in Pennsylvania have made Toomey a lightning rod, protesting outside his offices and hounding him over his votes and support for Trump. He would have faced much more vehement and energized opposition in 2022.

Toomey also may have struggled to re-create his 2016 victory, when he held down his losses in the Philadelphia suburbs, far outperforming Trump there. Since then, the GOP support in that area has cratered. Meanwhile, Toomey’s buttoned-up style and personality may not have been able to draw the same level of working-class, rural support Trump has to make up the difference.

Toomey allies argued that he could have won, and that his approach would still fare better in swing areas than Trump’s. But they said he wanted to see more of his children, ages 10, 19, and 20, and that gridlock in Washington was a concern.

“It’s frustrating in D.C. right now,” said Josh Novotney, a longtime Toomey political adviser from Philadelphia. “He’s not the type of guy to go down there just to accrue seniority. He’s the type of guy who wants to actually get something done."

Toomey said his priorities for the next two years include making some of the recent tax code changes permanent and pursuing free trade agreements with other parts of the world, such as countries in Asia and the European Union (something that may put the free-market-supporting senator at odds with Trump). He also wants to expand investment opportunities for middle-income families, he said.