'I have given up': Democratic donors plot to finance primary challenge against Kyrsten Sinema

Those who declined to be named in this story did so in order to speak freely.

Sinema, who will not face reelection until 2024, has helped to sink some of her party's priorities. She drew ire from Democrats last week when she voted against changing the Senate's filibuster rules to pass voting rights legislation.

She also has opposed raising the federal minimum wage to $15 per hour and increasing the corporate tax rate.

Sinema's record has led at least one congressional colleague from her state to consider trying to unseat her. Rep. Ruben Gallego, D-Ariz., has said he recently met with party donors, including those who once supported Sinema. In many cases, they assured him they would back him in a possible primary challenge against the Arizona senator.

Gallego, who opted not to run in 2020 against now-Sen. Mark Kelly, D-Ariz., said he would not make a decision about whether to run against Sinema until after the crucial 2022 midterm elections.

Gallego, who is considered a progressive, called out Sinema by name earlier this month on the House floor as he backed elections legislation. The Iraq War veteran has previously said he supports liberal priorities such as "Medicare for All."

Representatives for Gallego and Sinema did not return requests for comment.

A recent poll by OH Predictive Insights found that "only 26% of Arizona Democrats said that they would prefer Sinema, while another 72% chose a Democrat other" than her in a hypothetical 2024 primary. It surveyed more than 700 registered voters in Arizona.

Despite the pushback she has received from her own party, Sinema has enjoyed fundraising success throughout the 2022 election cycle. She has raised more than $2 million in part through contributions from corporate PACs tied to AT&T, Amazon, Horizon Therapeutics and Airbus Group.

While Sinema's opposition has made her an influential vote in a Senate split 50-50 by party, donors who are passionate about Democratic priorities are discussing a move to fund efforts that could force her out of Congress. Her resistance to key party policies has led to the creation of at least three political action committees that aim to unseat her.

"I have given up really trying to understand Sinema's motivations for the way she votes. And at a certain point I don't care. I just know if there is an alternative I will back them. And I know other people feel that way," a past Sinema donor who no longer supports her explained to CNBC.

Though Sinema has said she backs voting rights bills before the Senate, she and conservative Sen. Joe Manchin, D-W.Va, voted against an effort to change the filibuster rules to pass the elections plans without Republican support. Those votes effectively ended any chance to approve legislation that Democrats argue will boost access to the ballot box.

Since then, leaders of the Arizona Democratic Party voted to censure Sinema. Emily's List, an outside group that backs Democratic women who support abortion rights, said it would withdraw support for the Arizona lawmaker. Emily's List contributed $10,000 to Sinema's 2018 campaign through its political action committee, according to data from the nonpartisan Center for Responsive Politics.

Even before the filibuster vote, Democratic donors started to plan how they can contribute to a primary challenge against Sinema.

Trey Beck, a philanthropist and major party financier has told allies he plans to invest in a primary against Sinema, according to people familiar with the matter. Beck was one of the party donors who spoke to Gallego about a potential primary challenge.

He contributed at least $2,700 to Sinema's campaign in 2018, according to CRP data. Beck also signed the letter in which donors criticized the senator's stances and suggested their donations should be returned.

Beck, who was a managing director at investment firm D.E. Shaw Group, has given to Democratic-aligned groups for years. He gave five-figure donations to the Democratic National Committee, the Senate Majority PAC and Priorities USA Action. Beck declined to comment.

Luis A. Miranda Jr., father of actor Lin-Manuel Miranda and a veteran political strategist, has spoken to Gallego about a potential primary, his spokesman told CNBC on Tuesday. Miranda has worked with senior party leaders, including Senate Majority Leader Chuck Schumer, D-N.Y., Sen. Kirsten Gillibrand, D-N.Y., and former New York Sen. Hillary Clinton.

Miranda Jr. was also one of the Democrats who signed the letter to Sinema. Records show he has not contributed to her campaign. He has, however, donated to Democratic candidates and organizations including the Latino Victory Fund.

Party bundlers who have fundraised for President Joe Biden, Vice President Kamala Harris and former President Barack Obama are eager to raise money for a primary against Sinema, people who spoke to CNBC explained.

A bundler who raised at least $500,000 for Obama's 2012 run for president told CNBC that they discussed a possible primary run with Gallego as far back as December. This person, who declined to be named in order to speak openly about the potential campaign, told Gallego he would see their support. The person also contributed to Sinema's 2018 Senate campaign.

When Gallego recently visited New York, donors from a wide variety of industries including Wall Street were asked to meet with him to discuss his political future.

Some who could not make the meetings due to prior commitments told CNBC they would have met with Gallego if they knew he was considering taking on Sinema.

"I would have said yes had I known he was thinking about challenging that clown," said one longtime party donor who has fundraised for Harris and Biden.