Groups committed to giving parents the option of sending their children to private schools using taxpayer dollars — sometimes known as “school choice” or “vouchers” — have given millions of dollars to Republican candidates in Texas this year. Political observers said as a result, public school funding is effectively on the ballot in the state during Tuesday’s elections.

The push for private school vouchers has been funded in large part by Defend Texas Liberty, a Christian nationalist-aligned political action committee led by a former far-right Republican state lawmaker and bankrolled by a pair of West Texas billionaires. According to an NBC News analysis of Texas Ethics Commission campaign finance reports and data compiled by the nonprofit OpenSecrets, the PAC has spent nearly $10 million this year, largely backing Republican candidates who support school choice and attacking those who oppose it.

“These groups have been demonizing what is being taught in public schools, and that’s the fastest way to erode faith that public schools work,” Brandon Rottinghaus, a political scientist at the University of Houston, said. “Whether it’s true or not is irrelevant. If people believe that it’s true, then it’s politically potent.”

Defend Texas Liberty gave $3.6 million to former state lawmaker Don Huffines, who ran against Gov. Greg Abbott, R-Texas, in the Texas Republican gubernatorial primary. Huffines promised to crack down on medical care for transgender children, require the teaching of creationism in public schools and give parents government money to send their children to private schools.

The PAC also spent $168,000 supporting Republican Nate Schatzline, a former pastor running for a seat in the Texas House of Representatives. Schatzline won a competitive GOP primary in a solidly conservative North Texas district in part by painting his Republican opponent as an advocate for teaching “leftist, woke ideologies” in schools.

Gov. Greg Abbott recently pledged to make school choice a priority in the next legislative session if he wins re-election over Democratic challenger Beto O’Rourke. This fall, Defend Texas Liberty spent $100,000 to put up dozens of billboards along Texas highways, including some that showed a photo of O’Rourke next to a baseless allegation about “grooming” children, an anti-LGBTQ attack that’s become popular among conservatives this year.

“Abbott is now calling to defund public education with his voucher program that takes tax dollars out of public school classrooms across the state and sends them away to private schools,” Tori Larned, a spokesperson for O’Rourke’s campaign, said.