Republican Kari Lake, a Donald Trump ally who has refused to acknowledge her loss in last year's race for Arizona governor, will soon launch her campaign for the U.S. Senate seat held by independent Kyrsten Sinema, a senior adviser said Thursday.

What You Need To Know

  • Donald Trump ally Kari Lake, who's refused to acknowledge her loss in last year’s race for Arizona governor, is now running for U.S. Senate
  • A senior adviser says Lake will formally launch her campaign on Oct. 10. Lake is seeking the Republican nomination for the Senate seat now held by independent Kyrsten Sinema, a former Democrat
  • Lake’s entrance in one of next year’s top Senate contests complicates Republican efforts to nominate candidates with broader appeal after a disappointing showing for the GOP in last year’s midterms
  • Lake is a former television anchor who's built an enthusiastic following with her unflinching support for Trump and her steadfast promotion of false claims of election fraud

Lake's entrance in one of next year's top Senate contests likely complicates Republican efforts to nominate candidates with a broader appeal after a disappointing showing for the party in last year's midterms. She will enter the race as the front-runner for the GOP nomination.

Caroline Wren, a senior adviser to Lake, confirmed that she will open her campaign with an Oct. 10 rally. The Wall Street Journal first reported the news.

A charismatic former television anchor who is well known in the Phoenix market, Lake built an enthusiastic following among Republicans with her unflinching support for Trump and her steadfast promotion of false claims of election fraud.

Lake's star power stretches far beyond Arizona. Lake is seen as a potential running mate for Trump, who is leading polls for the Republican presidential nomination.

The Arizona race is a top target for Republicans looking to regain the Senate, where Democrats hold a 51-49 edge that includes Sinema, who left the Democratic Party in 2022 but still receives her committees assignments from Democrats. The 2024 Senate map heavily favors the GOP, with Democratic-held seats up for grabs in three states that Trump won in 2020.

Courts have repeatedly rejected Lake's lawsuits challenging last year's election results. The litigation has juiced Lake's fundraising but not advanced her false claim to be the “duly elected governor” Arizona, rather than Democrat Katie Hobbs.

Lake joins Pinal County Sheriff Mark Lamb in the Republican Senate primary. Several other Republicans have considered running but have stayed out of the race while Lake considered her plans. They include Blake Masters, Jim Lamon and Karrin Taylor Robson, all businesspeople who lost 2022 races for Senate or governor.

U.S. Rep. Ruben Gallego, an Iraq War veteran and one of the most prominent Latino officials in Arizona, is the only major Democrat in the race.

Sinema is raising money for a potential reelection campaign and is stepping up her public appearances in Arizona, but she has said she's in no hurry to decide whether to seek a second term in the Senate. Her party switch came after she had infuriated many Democrats who saw her as too close to business interests and an impediment to progressive change.

Lake's presence in the race could help Sinema if she chooses to mount an independent campaign for reelection. Lake alienated many establishment Republicans during her campaign for governor, even telling “McCain Republicans” to “get the hell out” of a campaign event, describing the late and beloved Arizona Sen. John McCain a “loser.”

To win, Sinema will need to win over a sizable chunk of Republicans and Democrats along with a majority of independents.

Until Trump's presidency, Arizona had been a reliably Republican state since World War II. Republicans still maintain a registration edge over Democrats, but the GOP lost three consecutive Senate races and last year watched Democrats win the top state offices over a slate of Trump-endorsed election deniers, including Lake.

The state is emblematic of the party's struggles to win over suburban voters turned off by Trump. In Lake's loss last year, 11% of voters who identified as Republicans backed Hobbs, including 25% of Republicans who identified as moderate or liberal, according to AP VoteCast, an expansive survey of more than 3,200 voters in Arizona.

Democrats posted surprising success in last year's Senate races despite a tough economic picture and an unpopular Democratic president after voters rejected Trump-backed Republican nominees in battleground states, including Arizona. Republicans in Washington have pledged to take a more active posture in primaries next year, hoping to ensure the party nominates candidates who can win in November.

GOP officials in Washington have taken a wait-and-see approach to the Arizona race, viewing Lake as the odds-on favorite to win the primary but fearing the serious baggage she would carry into a general election.