WASHINGTON — The John Cornyn-Ken Paxton Senate runoff may be sucking up most of the political oxygen in Texas, but outside groups are pouring millions more into the state’s key U.S. House runoffs.

With under two weeks to go until the May 26 runoff, an array of political action committees — some powered by untraceable dark money — has spent close to $6 million since the March 3 primary across seven of Texas’ most meaningful congressional runoffs.

They range from perennial players, like the Democratic centrist Blue Dog PAC and the conservative Club for Growth, to well-heeled PACs supporting the cryptocurrency and artificial intelligence industries. And one mysterious group seemingly aligned with the GOP is boosting a candidate with a history of antisemitic comments in a San Antonio-area Democratic primary, suggesting an effort to line up a candidate the party sees as more easily beatable.

Voters from Abilene to Dallas to Houston to Lubbock are being blitzed with ads, mailers and texts from these groups. And while overall House ad spending on television, digital and radio lags prior cycles, the share covered by outside sources has skyrocketed, according to AdImpact, an ad tracking firm.

Of the nearly $4.6 million shelled out for TV, digital and radio ads in Texas’ congressional runoffs, 89% has come from PACs, super PACs and nonprofits operating independently from the candidates. That’s up from 29% in 2020; 50% in 2022; and 68% last cycle, per AdImpact.

Some of the phenomenon can be traced to last year’s GOP redistricting, which yielded a wave of competitive primaries by forcing Democrats into overlapping districts and creating free-for-alls for newly drawn seats where there is no incumbent. It is also a sign of the political stakes in Congress’ lower chamber, with party leaders and other insiders keen to put forward the most competitive nominees for a general election that will decide control of a closely divided House.

With limited budgets of their own, candidates may also be relying on more deep-pocketed outside groups to break through the noise of the pricey U.S. Senate and attorney general runoffs, which have otherwise dominated the airwaves.

The influence of outside spending is perhaps most notable in the 35th Congressional District, where a pop-up PAC apparently linked to the GOP is spending to boost a fringe candidate in the Democratic runoff. The district is among the five seats targeted by Republicans’ new redistricting map.

Maureen Galindo, a progressive sex therapist who has raised little money, finished first in the Democratic primary with 29.2% of the vote. Galindo has trafficked in antisemitic conspiracies, saying Jews run Hollywood and referring to the “synagogue of Satan.”

She is running against Bexar County sheriff’s deputy Johnny Garcia, who finished second in March with 27% of the vote and is backed by the Democratic Congressional Campaign Committee — House Democrats’ main campaign arm — and the centrist Blue Dog PAC. The runoff is highly consequential to both parties, given that the Texas Legislature redrew the San Antonio-area seat last summer to favor Republicans. The district would have voted for Donald Trump by a 10-point margin in 2024; it is majority-Hispanic, fueling Democratic hopes of overcoming the gerrymander if they can make up lost ground with Hispanic voters.

Galindo first received outside support on May 6, when a shadowy group called Lead Left PAC spent over $40,000 on pro-Galindo mailers touting her progressive credentials. The group, which registered as a PAC in late April, will not have to report its donors until after the runoff. But the metadata of its website included links to Republican fundraising platform WinRed.

Lead Left PAC has since placed an $80,000 ad buy, according to AdImpact, and dropped additional mailers, bringing its total spend to over $340,000.

“This has now become an all-out arms race,” Garcia said. “Republicans are frightened for me to make it out of the runoff.”

In the wake of Democratic outrage over Galindo’s comments and Republican meddling, Garcia received the endorsement of Rep. Greg Casar, D-Austin, the Congressional Progressive Caucus chair whose district was redrawn to form the one Garcia is running for.

Galindo, for her part, said over text that she doesn’t believe Republicans are behind the spending, because, “I don’t trust anything in the establishment political and media world.” She said she’s the strongest candidate in the general election and that the recent focus on the race, including being accused of antisemitism, has increased her reach.

“Even after this recent smear campaign claiming I’m antisemitic for being anti-Zionist has boosted my broad support,” she said. “We know what we see WITH OUR EYES and are sick of politicians and media trying to gaslight us. Zionists are the anti-semities.”

Beyond suspected GOP spending in the 35th District, outside groups are deploying millions in safe districts where the primary is the true contest.

The most expensive House runoff in Texas is the contest between two sitting members of Congress, Houston Democratic Reps. Al Green and Christian Menefee, in the 18th Congressional District. Fittingly, it includes the single biggest spender — Protect Progress, a pro-crypto super PAC powered by the blockchain industry.

Protect Progress has spent $1.8 million on the airwaves and over $350,000 on mail pieces supporting Menefee in the runoff. One of the group’s TV ads praises Menefee’s record and calls for voters to “pass the torch” to the new congressman, who is 40 years younger than Green. Another features Rep. Jasmine Crockett, D-Dallas, who endorsed Menefee. Cryptocurrency is never mentioned.

“Democrats used to be the party of the future, but lately, we’ve been running on the past — and losing,” the ad’s narrator says. “It’s time to pass the torch — and Democrat Christian Menefee is ready to continue the fight.”

Similarly, in Texas’ 19th Congressional District, where Lubbock agriculture lobbyist Tom Sell is facing conservative activist Abraham Enriquez, a pro-AI super PAC is the biggest runoff spender. American Mission, a Republican group connected to OpenAI’s political network that favors light-touch AI regulation, has spent nearly $600,000 airing a biographical ad about Sell that never mentions AI.

The Sell campaign, by contrast, has spent under $200,000 on ads, per AdImpact. Enriquez has spent less than $5,000.

The AI industry is playing in the 9th Congressional District as well — through a rival group. Defending Our Values PAC, which is affiliated with an Anthropic-backed effort to install candidates favoring heavier industry guardrails, has spent over $400,000 backing Alex Mealer and opposing her GOP runoff opponent, state Rep. Briscoe Cain.

The PAC has also spent over $560,000 supporting Carlos De La Cruz in the Republican runoff in the 35th District, running ads touting his Trump endorsement that also do not mention AI.

Seven different conservative groups have spent money in the 9th District Republican runoff, a contest that pits Mealer, a Trump-backed veteran, against the Abbott-backed Cain. Nearly all are working to get Mealer, who finished first in the primary, over the hump in the runoff.

The Club for Growth, an influential conservative group with significant fundraising prowess, endorsed Mealer. Between the group’s action fund and an outside group tied to CFG called Win It Back PAC, they’ve spent over $1.1 million to boost Mealer and oppose Cain. Their investment has included everything from a door-to-door field program to mailers to text messaging to ads.

On the airwaves, Win It Back PAC spent over $280,000 on an anti-Cain ad attacking the state lawmaker for receiving past campaign contributions from the developers of the controversial Colony Ridge project. The development, located in the Liberty County territory newly added to the 9th District, came under Republican scrutiny for selling land to undocumented immigrants.

“Briscoe Cain said Colony Ridge represented the American Dream,” the ad’s narrator says over spooky visuals. “So out of touch, it’s scary.”

There’s been over $650,000 in TV, digital and radio ad spending alone in the 9th District runoff — more than 99% of which comes from outside groups backing Mealer. Conservatives for American Excellence, a super PAC funded by GOP megadonors that has intervened in past Republican primaries against prospective Freedom Caucus hardliners, has put over $370,000 into an ad bashing Cain as a “liberal lightweight.”

The same group has also spent over $40,000 on pro-Sell mail in the 19th District.

Cain, a Republican from Deer Park, has routinely been among the most conservative lawmakers at the Capitol over nearly a decade in the state House. But he has come under fire from Mealer for supporting the lower chamber’s impeachment push against Paxton in 2023.

The only outside group supporting Cain in the runoff is a group called Building a Strong America, which received all of its funding from a dark money group that does not need to disclose its donors. The group has funded over $85,000 in anti-Mealer texts and digital ads.

This article first appeared on The Texas Tribune.