PHOENIX — The head Democratic member of the U.S. Senate will reportedly support Rep. Kyrsten Sinema (D-Ariz.) if she runs for Jeff Flake’s seat in the 2018 Senate race, The Hill reported on Monday.

During the August recess, Senate Minority Leader Charles Schumer of New York reportedly told Sinema that he would back her over other Democratic primary candidates, multiple sources told the publication.

Schumer also reportedly called Phoenix Mayor Greg Stanton and told him that he would back Sinema. Neither Sinema nor Stanton have launched an official Senate campaign, but both politicians have been floated for the Democratic primaries. Sinema expressed interest in running for Senate last month.

The Hill said the calls were the “clearest sign yet” that Sinema is “gearing up for a Senate run” and that a campaign announcement is expected “any day.”

Former Rep. Matt Salmon (R-Ariz.), who was also once rumored to run for the Senate seat, called Sinema a “formidable challenger.”

“She’s done a very effective job working across the aisle. And she voted against Nancy Pelosi twice for Speaker,” Salmon told The Hill.

Flake faces tough reelection battle

Flake is running for reelection against Kelli Ward, another Republican candidate who ran for Sen. John McCain’s seat in 2016 and lost.

Arizona Treasurer Jeff DeWit and Robert Graham, former head of the Arizona Republican Party, have also been rumored to run for Senate, but neither have announced an official campaign.

Deedra Abboud, Jim Moss, Chris Russell and Richard Sherzan are running in the Democratic primary election for the Arizona Senate seat.

Spokespeople for Sinema, Stanton and Schumer did not offer a comment to The Hill for the story.

According to a HighGround poll from August, Ward was leading Flake 43 percent to 28 percent, but the poll also showed Sinema beating Flake in a match-up, 41 percent to 33 percent.

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