A newly leaked poll of Arizona voters suggests that Senator Sinema, if she does run for re-election, could hurt Republicans more than Democrats in the race for Senate there in 2024.

A National Republican Senatorial Committee poll, obtained by Punchbowl News, found that in a head-to-head matchup against Congressman Ruben Gallego, Kari Lake, the TV news host who is current favorite for the GOP nomination in Arizona, trails Mr. Gallego by 5 points, 49 percent to 44 percent.

The survey also found that in a three-way matchup between Mr. Gallego, Ms. Lake, and Ms. Sinema running as an independent, Mr. Gallego would lead with 41 percent support to Ms. Lake’s 37 percent and Ms. Sinema’s 17 percent.

The numbers from the GOP committee are nearly identical to polling done by Mr. Gallego’s campaign committee earlier this year, which found Mr. Gallego would lead the same matchup with 41 percent support to Ms. Lake’s 36 percent and Ms. Sinema’s 15 percent.

Both polls suggest that Republicans will have an uphill battle in the state, which has been trending toward supporting Democratic candidates in recent years.

In 2022, Senator Kelly defeated the GOP nominee, venture capitalist Blake Masters, 51 percent to 47 percent. In the 2022 gubernatorial race, Ms. Lake lost by less than a point to Governor Hobbs.

Since the 2022 elections, Ms. Lake has claimed that she is actually the rightful winner of the 2022 election for governor there, though she has lost multiple legal challenges to the election results.

Ms. Lake’s denial of election results has become even more central to her political identity than it was in her 2022 campaign, and it’s not clear that she will be more popular with voters because of it.

A political scientist at the University of Arizona and the former mayor of Tucson, Thomas Volgy, tells the Sun that he thinks that “reality in Arizona is fairly well reflected in the poll results.”

“Lake may be very popular with the MAGA voter, but in terms of the rest of the electorate in Arizona I believe the support for her has shrunk rather than increased after the 2022 elections, and in good part over the insane set of lawsuits challenging the results without much justification,” Mr. Volgy says.

Mr. Volgy adds that Ms. Lake’s “political attacks on Maricopa County Republican elected officials also didn’t go down very well with either Republicans (who are not MAGA) or Independents.”

This past summer, the Maricopa County recorder, Stephen Richer, sued Ms. Lake for defamation over claims made by Ms. Lake and her campaign that Mr. Richer added 300,000 “illegal” ballots into the Maricopa County count.

“So, while it may be possible (or even likely) that she will become the nominee of her party, her chances of actually winning the general election, and especially in a three-way race, is quite unlikely in my book,” Mr. Volgy adds. “I think in a two-way race, her chances may be a bit better.”