Rep. Martha McSally tells House colleagues she is running for Senate

Congresswoman Martha McSally is planning to enter Arizona's 2018 Senate race, giving Republican Kelli Ward new competition in the GOP primary.

The lawmaker has told her Republican colleagues in Arizona's delegation that she intends to enter the Senate race, but didn't indicate when she would formally announce her bid, according to two people with knowledge of the conversations.

Her decision will further shake up the state's political landscape. Sen. Jeff Flake announced two weeks ago he was abandoning his re-election bid amid sinking polling and high-profile clashes with President Donald Trump.

McSally would be the first high-profile name to join the Senate race since Flake's retirement announcement. Jay Heiler, a longtime lobbyist and member of the state's Board of Regents, has formed an exploratory committee. Others, including former members of Congress Matt Salmon and John Shadegg, have weighed a Senate bid, but have taken a pass, at least for now.

RELATED: Senate poll: GOP voters uncertain who they want to replace Jeff Flake

Republican primary fight looms

McSally has been especially tight-lipped about the races, but seemed to telegraph a Senate run last week in her campaign's response to an attack from a political group supporting Ward.

In the response, McSally echoed Trump's familiar charge of "fake news" and embraced an assessment of her record as Arizona's most reliable vote for the Trump administration. McSally has avoided commenting on Trump's many controversies throughout the 2016 presidential campaign and since Trump has taken office.

But McSally can expect opposition from some on the right, including a political-action committee aligned with the conservative Club for Growth, which warned recently that it would oppose her candidacy. 

Ward's campaign said they are ready for the competition.

“Arizona has had some great conservatives in Congress — unfortunately, Martha McSally isn't one of them," said Ed Rollins, Ward's campaign chairman. "If you like Jeff Flake, John McCain and Krysten Sinema — you'll love Martha McSally. She's not the conservative Republican that she claims to be, and we will make sure the voters of Arizona know this if she decides to jump into the race.”

Democrats also attacked McSally's entry and sought to link her to Senate Majority Leader Mitch McConnell, whose popularity has plummeted among conservatives as Trump has struggled to achieve significant legislative victories so far this year.

“Mitch McConnell's Martha McSally — who has already earned the ire of conservatives — will take up the same establishment campaign that forced Sen. Jeff Flake to sprint out the door, and this attempted coronation will only continue the GOP civil war in Arizona," said Herschel Fink, executive director of the Arizona Democratic Party. "With her vocal enthusiasm for taking away health care from Arizonans and support for raising taxes on hardworking middle-class families, McConnell's McSally represents the problem voters see with Washington. Good luck selling that to Arizonans.”  

A challenging re-election race

McSally, who represents the Tucson-based 2nd Congressional District, was already facing a difficult re-election campaign to the House.

Last year she breezed to a second term in the evenly divided district, but has faced anger from many there for supporting the Trump agenda, especially since voting in May for the failed GOP-led health-care overhaul.

McSally trailed in some polls and faced formidable Democratic opposition led by former Congresswoman Ann Kirkpatrick, an adept fundraiser who has consolidated her party's establishment support and the money that goes with it.

So far, McSally's voting record has made her the most supportive of the Trump agenda among Arizona's House members, as tracked by the website FiveThirtyEight. That has been a mill stone in her divided district but could be an asset in securing the GOP nomination in a statewide Senate race.

McSally will likely lean heavily on her military background as the first woman to fly a combat mission for the Air Force. She is a prolific fundraiser and seen as a steady hand who could expect significant support from a wider network of party donors.

By contrast, Ward, a former state senator, has struggled to raise money this year, though her campaign said contributions have soared since Trump posted a supportive tweet for her in August.

In only her second term, House leaders made McSally chairwoman of a Homeland Security subcommittee, a sign of her loyalty to them and of their confidence in her political future.

Others steer clear of Senate race

The four other Republicans in Arizona's House delegation have also steered clear of the Senate race. 

Rep. Paul Gosar has flirted with running for the Senate — mentioning it after Flake's retirement speech — but has remained out of the race so far.  He also entertained challenging Sen. John McCain in 2016 before deciding to run for re-election to his House seat.

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Rep. Trent Franks, the most senior House Republican from Arizona, could be in line to chair a subcommittee after next year's elections, and Rep. David Schweikert is said to eye a run for governor in 2022. 

McSally's plan creates a vacuum for Republicans in her district and will give new confidence to Democrats, who will instantly view her House seat as key to winning the net 24 seats needed to retake the House majority.

McSally's move also adds another woman to a Senate race that already has at least three female contenders. In addition to Ward, Rep. Kyrsten Sinema is vying for the Democratic nomination against political newcomer Deedra Abboud.

Reporters Eliza Collins and Yvonne Wingett Sanchez contributed to this article.

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