At a confirmation hearing earlier this month, Betsy DeVos, President Trump’s pick for education secretary, responded to a question about whether she would promote “junk science” by saying she supports science teaching that “allows students to exercise critical thinking.”

This seemingly innocuous statement has raised alarms among science education advocates, and buoyed the hopes of conservative Christian groups that, if confirmed, DeVos may use her bully pulpit atop the U.S. Department of Education to undermine the teaching of evolution in public schools.

DeVos and her family have poured millions of dollars into groups that champion intelligent design, the doctrine that the complexity of biological life can best be explained by the existence of a creator rather than by Darwinian evolution. Within this movement, “critical thinking” has become a code phrase to justify teaching of intelligent design.

Candi Cushman, a policy analyst for the conservative Christian group Focus on the Family, described DeVos’ nomination as a positive development for communities that want to include intelligent design in their school curricula. Both the Dick and Betsy DeVos Foundation and Betsy DeVos’ mother’s foundation have donated to Focus on the Family, which has promoted intelligent design.

“Mrs. DeVos will work toward ensuring parents and educators have a powerful voice at the local level on multiple issues, including science curriculum,” wrote Cushman in an email.

DeVos has not publicly spoken about her personal views on intelligent design. A more nuanced outgrowth of creationism, the approach lost steam after a federal court ruled a decade ago that teaching it in public schools would violate the separation of church and state. Greg McNeilly, a longtime aide to DeVos and an executive at her and her husband’s privately held investment management firm, the Windquest Group, said he knows from personal discussions with DeVos that she does not believe that intelligent design should be taught in public schools. He added that her personal beliefs on the theory, whatever they are, shouldn’t matter.

“I don’t know the answer to whether she believes in intelligent design — it’s not relevant,” McNeilly told ProPublica. “There is no debate on intelligent design or creationism being taught in schools. According to federal law, it cannot be taught.”

That assurance provides little comfort to those who worry that DeVos’ nomination could erode public schools’ commitment to teaching evolution.

Hearing DeVos refer to “critical thinking” was “like hearing old catch phrases from a nearly forgotten TV show that never made prime time,” Michigan State University professor Robert Pennock told ProPublica. Pennock has written several books and articles about creationism and intelligent design, including “The Tower of Babel: The Evidence Against the New Creationism” (2000), and has testified as an expert witness that intelligent design should not be studied in public school science courses.

“She evaded what should have been a simple question about not teaching junk science,” Pennock wrote in an email. “More than that, she did so in a way that signaled her willingness to open the door to intelligent design creationism.”

A confirmation vote in the Senate Health, Education, Labor & Pensions Committee is expected Tuesday on DeVos, a billionaire and longtime advocate of charter schools, voucher programs and other alternatives to traditional public education. She attended a Christian high school and college, and her four children were either home-schooled or sent to religious high school. Her husband, Amway heir Dick DeVos, publicly supported intelligent design during a failed campaign for governor of Michigan in 2006.

Many Christians who accept the Bible and its creation story as literal truth have long opposed teaching evolution as fact. Intelligent design gained traction in the 1990s and early 2000s, when Christian groups pushed for it to be taught in public schools, often alongside lessons on evolution. They distributed intelligent design textbooks and lesson plans, but faced a backlash from the scientific community and the courts. Kansas and Ohio adopted science standards, which were later rescinded, calling for teaching of “critical analysis” of evolution. While public schools are not legally allowed to teach intelligent design in science class, numerous private religious schools and some colleges do.

Advocates have contended that presenting intelligent design side-by-side with evolution, also known as “teaching the controversy,” would enhance the critical thinking skills of students and improve their scientific reasoning. Indeed, a briefing packet for educators from the leading intelligent design group, the Seattle-based Discovery Institute, walks teachers through this approach.

“In American public education today, the status quo teaches evolution in a dogmatic, pro-Darwin-only fashion which fails to help students use critical thinking on this topic,” the report states, adding that teaching “the controversy” can help students “learn the critical thinking skills they need to think like good scientists.”

John West, vice president of the Discovery Institute, said that the implication that “critical thinking” is code for intelligent design is “ludicrous.”

“Critical thinking is a pretty foundational idea supported by lots of people, not just us,” said West in an email, adding that he also thinks “critical thinking should apply to discussions of evolution.”

In one of the most high-profile legal cases on teaching evolution since the Scopes trial in 1925, civil-liberties organizations took the Dover, Pennsylvania, school district to federal district court in Harrisburg in 2005, because the school board had required ninth-grade biology students to be told that the theory of evolution was flawed and that intelligent design was an alternative. Teachers were ordered to promote the 1989 intelligent design textbook “Of Pandas and People” as a reference.

The Thomas More Law Center, a Michigan-based Christian legal group whose slogan is “The Sword and the Shield for People of Faith,” represented the school district. The center had been searching for several years for a school board that favored teaching intelligent design and was willing to defend a lawsuit. Pennock, the Michigan State professor, testified as an expert witness for the plaintiffs. The district argued that the introduction of intelligent design in the classroom was intended to encourage “critical thinking,” but Judge John E. Jones ruled against it, stating that the doctrine had “utterly no place in science curriculum.”

“The goal of the intelligent design movement is not to encourage critical thought,” Jones wrote in his opinion, “but to foment a revolution which would supplant evolutionary theory with intelligent design.”

The Dick and Betsy DeVos Foundation contributed $15,000 to the Thomas More Law Center between 2001 and 2002, according to tax filings. The Edgar and Elsa Prince Foundation, the foundation of DeVos’ mother and deceased father, has donated over $1 million since 2002 to Alliance Defending Freedom, a conservative Christian legal group based in Scottsdale, Arizona. The group unsuccessfully attempted to intervene in the Dover case by representing the publisher of the intelligent design textbook. The Thomas More Law Center and Alliance Defending Freedom declined to answer any questions about DeVos.

The Prince Foundation’s tax filings listed DeVos as a vice president for more than a decade. In the days leading up to her Senate hearing, forms were filed on DeVos’ behalf with Michigan’s licensing department to withdraw her name from the group. She testified at the hearing that her recorded affiliation with the organization had been a “clerical error.”

“Betsy doesn’t sit around and Google herself to find out if she’s an officer of the foundation,” McNeilly told ProPublica, adding that DeVos had no influence at the foundation.

Based in Colorado Springs, Colorado, Focus on the Family has produced a religious video series with one episode focused on intelligent design and Darwinian evolution critiques. Through their foundation, DeVos and her husband contributed $75,000 to Focus on the Family in 2001, and her mother’s foundation has since donated almost $5 million.

Even though DeVos or her family may provide financial support to these organizations, it doesn’t necessarily mean that she agrees with all their views, McNeilly said.

“She gives to all sorts of organizations that are involved in a variety of issues,” he said. “She doesn’t do a litmus test to make sure she’s in agreement with everything.”

Voucher programs, which DeVos has long championed, often provide taxpayer funding for low-income students to enroll in private and religious schools, which may legally teach creationism and intelligent design. The question of whether voucher program support of religious schools violates the separation of church and state has led to legalchallenges in some states. Indeed, in 2015, Colorado’s Supreme Court struck down a school district’s voucher program because it was funneling public money to religious schools.

The Great Lakes Education Project, a group founded by DeVos and her husband, has been one of the primary vehicles for DeVos’ school-choice advocacy. Before her federal nomination, she served as a chairwoman and board member of the group. While Great Lakes has largely avoided religious rhetoric in its push for school choice, a policy paper released by the group in 2013 praised the standards initiative known as Common Core for leaving curriculum decisions in the hands of states and localities, including the option to teach intelligent design in public schools.

“State and local officials will continue to make important curriculum decisions when it comes to teaching History or specific issues such as Evolution or Intelligent Design, in line with what is right for their students and communities,” read the paper, which was printed on the group’s own letterhead and promoted on its website.

“It’s one sentence, but it says a lot,” said Heather Weaver, a senior staff attorney at the American Civil Liberties Union, who reviewed the document at ProPublica’s request. “The fact that her foundation was putting out materials saying that local and state officials can teach intelligent design is troubling. It shows a lack of understanding about the law and science education.”

Gary Naeyaert, executive director of the Great Lakes Education Project, told ProPublica that the organization did not write the paper and that it was drafted as part of a national advocacy effort to inform educators about Common Core. The paper didn’t cite the original source, a lapse that Naeyart attributed to a “design error.” He couldn’t recall which advocacy group was the author.

Although decisions on public school curricula are largely left to local school districts and state governments, the secretary of education’s views still carry weight, said Glenn Branch, deputy director of the National Center for Science Education, a nonprofit in Oakland, California.

“The secretary of education has an important bully pulpit,” said Branch. “It would be dismaying indeed if it were used to push creationism, climate change denial, or any other junk science.”