Arizona’s governor on Tuesday appointed U.S. Rep. Martha McSally to replace Sen. Jon Kyl in the seat that belonged to the late John McCain, sending the GOP congresswoman back to Washington just a month after she lost a tight race for the state’s other spot in the Senate.

McSally, a former air force colonel, lost to Democratic Rep. Kyrsten Sinema in November after a bruising contest in which she contended Sinema committed “treason” by making anti-war remarks in 2003. Now, McSally will join the Senate the same day that Sinema is sworn in.

“Arizona needs someone who understands the critical issues, can get to work on day one, and who embodies the spirit of service,” Gov. Doug Ducey said at a press conference.

The governor said Sinema will be sworn in first on Jan. 3 when the Senate reconvenes after the holidays, making her Arizona’s senior senator and its first woman in the chamber.

“I’m going to respect the will of the voters,” Ducey said.

McSally will serve until 2020, when voters will elect someone to finish the final two years of McCain’s term. She tried to put the heated campaign behind her.

“I look forward to working closely with Kyrsten Sinema in the Senate, as we did in the House,” McSally told reporters. “There’s a lot of common ground between us, and I’m ready to hit it running.”

Sinema’s spokesman didn’t respond to a request for comment Tuesday.

McSally also has tried to patch up frayed relations with the McCain family, whom she infuriated by following President Donald Trump’s lead and not mentioning the dying senator during a signing ceremony for a defense bill named after McCain. McSally met with McCain’s wife, Cindy, on Friday.

“My husband’s greatest legacy was placing service to AZ & USA ahead of his own self-interest,” Cindy McCain tweeted Tuesday. “I respect @dougducey’s decision to appoint @RepMcSally to fill the remainder of his term. Arizonans will be pulling for her, hoping that she will follow his example of selfless leadership.”

McSally said she would, calling the late senator an icon and hero and promising to commit “to the standard of service that Senator McCain held, putting country before self.”

McCain died of brain cancer in August, and his retired longtime colleague, Kyl, was appointed to his seat. Kyl said he would only commit to serving until the end of 2018 and has resigned effective Dec. 31.

McSally’s appointment puts Arizona back in the political spotlight a month after Democrats won their first statewide race in a decade. Democrats hope that the state swings again in 2020 and are expected to target it both in the presidential race and the contest for McCain’s seat.

U.S. Rep. Ruben Gallego, former astronaut and current gun control advocate Mark Kelly and former Arizona Attorney General Grant Woods, who left the GOP this year, have all considered running as Democrats for the post. That they are all men may have made appointing a woman that much more desirable to the GOP.

The intense interest in the seat was a factor in Ducey’s convoluted decisions. He initially appointed Kyl while the governor himself was campaigning for re-election. By picking Kyl, Ducey dodged tough political decisions that could have complicated his own re-election bid.

McSally is a two-term congresswoman long considered for the Senate by the state’s GOP establishment. The first female combat pilot, McSally once sued the U.S. military so she would not be required to wear a head covering while stationed in the Middle East. She rose to the rank of colonel in the Air Force before entering politics. She got a taste for it working for Kyl’s office as a national security aide.

McSally represented a swing district in Tucson that voted for Hillary Clinton in 2016. She carved out a reputation as a moderate who could win tough elections. That ended during this year’s Senate campaign.

She had been critical of Trump in 2016 but praised him during the midterm election and embraced a tougher stance on immigration. But McSally wasn’t able to defeat Sinema, who ran as a centrist and peeled away enough moderate Republicans to win by 2 percentage points.

In a postelection memo, McSally strategists argued that she did well in a strong Democratic year. Senate Majority Leader Mitch McConnell lobbied for Ducey to select her.

Still, many Arizona Republicans were disappointed by McSally’s campaign and questioned whether she would be the strongest choice for McCain’s seat. Ducey had limited choices — the GOP’s bench is thin in Arizona and McSally was the only woman with federal experience who had campaigned statewide recently.

Democrats attacked the appointment following McSally’s Senate defeat.

“Why appoint a loser when you could find a fresh face with a better shot in 2020?” the Democratic Senate Campaign Committee said in a statement.