Sinema, a moderate Democrat who is up for re-election in 2024, is at the center of a standoff within the Democratic Party over the future of President Joe Biden's infrastructure agenda, and she has faced strong criticism for holding up the package from more than the usual suspects on the disgruntled left.
The new Primary Sinema PAC does not plan to support a particular primary challenger. Instead, it will fund local groups to pressure Sinema and help build the support and infrastructure for an eventual candidate.
"We fought tirelessly to elect Kyrsten Sinema in 2018," said Alex Gomez and Tomas Robles, the co-executive directors of the group Living United for Change in Arizona, adding that they were disappointed that she has not done more on voting rights, climate change, immigration reform and other issues.
"Sinema has proven time and time again that she doesn't share these values, so it's time to organize and replace her with someone who does," they said.
Sinema, whose office did not comment, has vexed the left flank of her party on a variety of issues, from her support for the filibuster to her opposition to a $15-an-hour minimum wage.
The central committee of the Arizona Democratic Party voted overwhelmingly Saturday to pass a resolution criticizing Sinema for opposing filibuster reform, among other issues, and warned that she could face a no-confidence vote.
"There is still time for Senator Sinema to change course," said Luis Avila, a veteran Arizona progressive organizer backing the Primary Sinema PAC. "But if she does not, there will be consequences for her betrayal of the people who elected her."
A recent poll conducted by OH Predictive Insights, a Phoenix-based political research firm, found that just 56 percent of Arizona Democrats had favorable views of Sinema — 30 percent had unfavorable views — while 80 percent had positive views of their junior senator, Mark Kelly.
"Numbers like that could potentially open the door for primary challengers," said Jacob Joss of OH Predictive Insights.
Initial funding for the Primary Sinema PAC came from Way to Win, a national network of wealthy progressive donors that spent $110 million last year, with a major emphasis on Arizona and Georgia, where Biden, Kelly and two other Democratic Senate candidates scored victories in historically red states.
"The people of Arizona voted for Joe Biden and the Biden agenda," said Leah Hunt-Hendrix, a co-founder of Way to Win. "Sen. Sinema is opposing Biden's popular policies, which are supported by broad, bipartisan majorities of Arizonans. If she continues to stand in the way, then we're going to hold her accountable."
David Lucier, the president of the Arizona Veterans & Military Leadership Alliance, who is also supporting the primary effort, said pressure had to be applied to Sinema now, even though Kelly will face voters next year and Sinema will not until 2024. "We can't afford to wait and must start creating that groundswell now," he said.
In a separate effort, two dozen public officials and activists in Arizona launched their own campaign Wednesday to build a pot of money that will eventually be released to a candidate who challenges Sinema. They are using the fundraising platform Crowdpac.
The group includes state Sen. Martin Quezada, Maricopa County Democratic Party official Jade Duran, Indivisible West Phoenix co-leader Patricia Thomas, Progressive Democrats of America organizer Patti Serrano and Kai Newkirk, who leads the Arizona Coalition to End the Filibuster.
"Either Senator Sinema votes to end or reform the Jim Crow filibuster this year or we fund a primary challenge to replace her with someone who will," the group wrote.
A third effort, also launched Thursday, is aimed at drafting Arizona Democratic Rep. Ruben Gallego to run against Sinema.
The Run Ruben Run campaign is a project of Nuestro PAC, which is focused on Latino mobilization and was founded by a former top advisor to the presidential campaign of Sen. Bernie Sanders, I-Vt.
Asked about running for Senate in 2024, Gallego said Thursday his attention is elsewhere.
"I'm focused on being a member of Congress and running for re-election," he said. "We need to focus on one thing right now which is passing reconciliation and passing [the bipartisan infrastructure plan] and not worry about these outside politics."
When NBC News reminded him that a senator is also a member of Congress, he laughed and said he meant he's focused on being a "House member."
CORRECTION (Sept. 30, 2021, 9:10 a.m. ET): A previous version of a photo caption with this article misspelled the first name of a senator from Arizona. She is Kyrsten Sinema, not Kirsten.