Pat Hardy, a 12-year incumbent on the State Board of Education, is facing a tough challenge from a conservative activist in a Republican primary runoff that could shift the balance of power on the board.

Tea Party groups in the district, which includes Parker County and parts of Tarrant and Dallas counties, have thrown their support behind Hardy's opponent, Eric Mahroum of Fort Worth, a restaurant manager who has no teaching or school administrative experience and is expected to vote with the far-right voting bloc on the 15-member, Republican-dominated board. Hardy has drawn criticism for taking votes with Democrats on the board, including on issues like teaching creationism alongside evolution in the state's public schools.

“Potentially, this race could alter the ideological balance of power on the board,” said Dan Quinn, a spokesman for the Texas Freedom Network, an organization that monitors religious influence in Texas schools. “The key difference between Pat Hardy and the other conservatives is that she refuses to vote in the rigid obedience of whatever [the far-right bloc] wants, and that has made her their enemy.”

Mahroum, who received 43.5 percent of the vote in the March primary, said he decided to challenge Hardy because she was too moderate for the conservative district. Hardy received 49.6 percent of the vote — just shy of the 50 percent she needed to avoid a runoff. Whichever Republican claims victory in the district will have a strong advantage over Democratic candidate Nancy Bean in the November general election.

“We need a fresh voice on that board. It’s time for her to go," Mahroum said of Hardy, adding, "She’s not conservative and she’s not representing her constituents."

Observers say the enthusiasm among conservatives for Mahroum may make it difficult for Hardy to prevail in the runoff, for which turnout will likely be low.

“One of the strengths of the Tea Party has been that they vote. For every election from dog catcher to president, they get out and vote very consistently,” said Monty Exter, a lobbyist for the Association of Texas Professional Educators, which has donated to Hardy. “If that’s true this time around and if the pro-education part of the electorate doesn’t also get out and vote, then Pat’s going to lose.”

Hardy, who taught social studies for 30 years, touts her experience on the board, including her tenure as the leader of the committee that oversees the Permanent School Fund. She dismissed criticism that she is too moderate and said she would continue to work with members of both parties.

“The goal should be to find a way to work out the issues that’s best for our children and for the state, not for any political bends,” Hardy said.

Hardy also emphasized her role as a liaison between the board members and educators.

“When I was first elected, there was this adversarial role between teachers and board members,” Hardy said. “But now, the professional expertise of math teachers or science teachers or social studies teachers is welcomed, even relied upon.”

Mahroum credited Hardy's experience as an educator but said she was no longer adequately representing her district.

“All the experience in the world is great, but she’s here for the Republican Party and that means she has to represent her party and our platform,” he said.

Debate has also flared in the race over CSCOPE, a state-approved curriculum system that conservatives have said promotes a liberal agenda.

“You have CSCOPE teaching our children that communism is okay, that the 9/11 terrorists were freedom fighters,” he said. “That does not need to be in the curriculum.”

Hardy said that Mahroum, like many people, misunderstands how CSCOPE works.

“CSCOPE was an attempt to bring curriculum to smaller school districts and those that don’t have the funding to create their own curriculum,” she said. "There's absolutely nothing demonic or diabolical about those lesson plans."

Disclosure: The Association of Texas Professional Educators is a corporate sponsor of The Texas Tribune. A complete list of Texas Tribune donors and sponsors can be viewed here.