Senator Sinema, unpopular among Democrats, independents, and Republicans, may play the spoiler for both of the major parties in the 2024 race for Senate in Arizona, new polling appears to confirm.

In January, the Sun reported that Ms. Sinema, who recently left the Democratic Party to become an independent, could end up hurting the Republican candidate nearly as much as her Democratic challenger, Ruben Gallego.

Now, polling conducted between January 18 and 23 by Jill Norminton of the polling and campaign strategy firm Normington Petts appears to show that Ms. Sinema would affect the hypothetical Republican candidate’s vote share in addition to Mr. Gallego’s.

The poll found that in a three-way race, Ms. Sinema consistently placed last. In a race between Mr. Gallego, failed Republican gubernatorial nominee Kari Lake, and Ms. Sinema, the candidates received 36 percent, 36 percent, and 24 percent support, respectively.

In a three-way race between Mr. Gallego, Governor Ducey, and Ms. Sinema, the candidates received 37 percent, 31 percent, and 27 percent of the vote, respectively. 

“It’s clear from this and previous surveys that Kyrsten Sinema has no path to re-election, but she could hand the seat to a MAGA Republican if we don’t stop her,” a spokeswoman for the Replace Sinema PAC, Sacha Haworth, said.

Breaking down the results of the three-way matchup between Mr. Gallego, Ms. Lake, and Ms. Sinema shows the latter pulling 14 points of her support from Mr. Gallego and nine points from Ms. Lake.

Without Ms. Sinema in the race, Mr. Gallego is the frontrunner in the matchup, leading Ms. Lake by five points, with 5 percent of voters undecided.

The president of Iconico and a strategist working with the Replace Sinema PAC, Luis Avila, said that Mr. Sinema’s opponents could potentially reduce support among Democrats even further before the election.

“Ruben Gallego is the frontrunner in this race, and the Replace Sinema PAC has to make sure that Sinema’s negatives stay so high that she can’t take more votes away from him and throw the race to Kari Lake or another MAGA Republican,” Mr. Avila said,

In an effort to explain why Mr. Gallego comes out on top in a three-way race, the poll also surveyed the favorability rating of the four candidates. Mr. Gallego was the only one with a statewide net positive rating.

Mr. Gallego enjoyed a net positive rating of 13 points, while Ms. Lake, Ms. Sinema, and Mr. Ducey all had negative ratings by 15 points, 13 points, and 20 points, respectively.