Rep. Ruben Gallego, a rumored primary challenger to Kyrsten Sinema, smashed his personal fundraising records in the first quarter of 2022

• Rep. Ruben Gallego is a possible primary challenger to Sen. Kyrsten Sinema in 2024.
• Gallego's campaign said he had his best fundraising quarter ever, raising $512,740.

Rep. Ruben Gallego, an Arizona Democrat and rumored primary challenger to Sen. Kyrsten Sinema in 2024, had a record fundraising quarter in the first three months of this year after Sinema faced a wave of progressive backlash.

Gallego will report raising $512,740 for his House race in the first three months of the year, which is almost four times more than his haul in the first quarter of 2020, his campaign confirmed to Insider. He raised a total of $1,824,000 over the course of the 2020 election cycle.

But it's not his congressional re-election that has Arizona's political establishment watching his fundraising numbers. After Sinema angered liberals and state party members by breaking from her fellow Senate Democrats on key votes and dooming legislative priorities for President Joe Biden, her critics have been hunting for a primary challenger to take her on from the left.

Groups backing a primary challenge to Sinema have raised hundreds of thousands of dollars so far, but it's unclear what — or who — will see the benefit of that money.

Gallego, a veteran who was elected to represent parts of Phoenix in 2014, has kept the door wide open for a potential Senate run.

"I've known Senator Sinema since we were both in our mid-20s and starting out in politics here in Arizona," Gallego said in January, after Sinema refused to vote with Senate Democrats to alter the chamber's filibuster rule. "The only consistency about Senator Sinema's roles and positions is inconsistency."

Gallego's seat is a safe one for Democrats, and he will likely coast to re-election to the House. But being able to flaunt his fundraising prowess now could put him in a strong position to benefit from the largesse of progressives who want an alternative to Sinema in the Senate.

Sinema is also a formidable fundraiser. She raised over $21 million for her 2018 Senate race, and has already raised $7.4 million for a 2024 re-election campaign.

Sinema's campaign did not immediately respond to a request for comment.