Sen. Rob Portman, a Republican from Ohio, announced Monday he will not seek reelection to a third term in 2022, ensuring a fierce and costly campaign for the open seat in a state Democrats are eager to wrest out of Republican control.

Portman, 65, cited his frustration with “partisan gridlock” as the impetus for his retirement. The decision comes two weeks before the Senate chamber is due to be convulsed by a second impeachment trial for former president Donald Trump.

“We live in an increasingly polarized country where members of both parties are being pushed further to the right and further to the left, and that means too few people who are actively looking to find common ground,” Portman said in a statement announcing his retirement. “This is not a new phenomenon, of course, but a problem that has gotten worse over the past few decades.”

The Democrats are taking control of the Senate as an impeachment trial, cabinet nominations and an ambitious Biden agenda are all on the table. (The Washington Post)

“This is a tough time to be in public service,” he added.

The surprise announcement by Portman, who first came to Congress as a House member in 1993 and later served as President George W. Bush’s budget director, follows the similar decision by Sen. Patrick J. Toomey, a Republican from neighboring Pennsylvania, to decline to seek a third term in 2022.

Portman’s decision set off a flurry of public consideration on both sides of the aisle.

Rep. Tim Ryan, who is the best-known among potential Democratic candidates, tweeted that he was “looking seriously” at running and included a donation link. He made a brief and unsuccessful bid for the Democratic presidential nomination in 2020.

The prohibitive favorite on the Republican side, if he chooses to run, is Rep. Jim Jordan, a Trump devotee who is well liked by the GOP base and is a known commodity for his near-daily appearances on Fox News. Jordan had no immediate comment on whether he would consider running.

Jordan, whose support of Trump was so fierce and provocative that he received the Medal of Freedom in the waning days of the administration, would be a departure from the more mild-mannered Portman.

Elected to the Senate in the 2010 tea party wave, Portman is a staunch fiscal conservative, but his genial demeanor has long made him appear more moderate compared with some of his fiery GOP colleagues. However, even as he distanced himself from Trump’s more incendiary rhetoric, he was a dependable vote for Trump during the former president’s single term.

For Democrats, the vacancy will serve as an opportunity to bolster their razor-thin majority in the 2022 midterm election. And for Republicans, the election could be an early test of whether the party’s now-dominant Trumpian wing can defeat the establishment Republicans who represented the state before the former president’s candidacy.

With its aging, mostly White population, Ohio has trended more conservative in recent years and has become a steeper climb for Democrats who in the 1980s and 1990s fared well in the state.

The state had long been a bellwether in presidential elections, siding with every presidential winner after 1960 until last year, when Trump defeated Biden by eight points while Biden easily won nationally.

Republicans also have won the last three statewide races for governor. The sole successful statewide Democrat in recent years has been the state’s senior senator, Sherrod Brown, a liberal who in 2018 won his third term.

Jeff Rusnak, a Democratic consultant in the state, called Portman’s exit “a once-in-a-generation opportunity for Ohio.”

“I think it’s a new day in Ohio, I think it’s wide open and it’s game-changing in a lot of ways and there’s a huge opportunity here for someone to emerge,” he said of Democrats’ chances.

But Corry Bliss, who ran Portman’s successful reelection campaign in 2016, laughed off the opposing party’s odds of taking the seat.

“The Ohio Democratic Party is dead, they’re inept, incompetent, they cannot and do not win races,” Bliss said.

As Portman lamented divisions in the Senate, former Ohio Democratic Party chairman David Pepper called him out, accusing him of not doing more during his time in the Senate to fight back against the vitriol.

“Those who could have made it a better environment, like Senator Portman, spent 10 years cowering and allowing it to become what it is now,” Pepper tweeted. But he also warned that Democrats “will need a strong candidate to keep the far right from winning this.”

Portman’s withdrawal means two perennial swing-state targets, Ohio and Pennsylvania, will have high-profile Senate races in 2022. Wisconsin also may host a nationally watched race as Democrats angle to unseat GOP Sen. Ron Johnson.

Already, in Pennsylvania, Lt. Gov. John Fetterman, a Democrat, has kicked off a formidable exploratory Senate campaign, raising more than $1 million in just two weeks.

Without the risk of a primary challenge, Portman and Toomey face less pressure as they consider a possible vote to convict Trump in the Senate impeachment trial next month. Toomey has signaled a willingness to hold Trump accountable for his role in inciting the violent mob that attacked the Capitol on Jan. 6, but Portman has expressed concern that doing so would deepen the nation’s polarization.