Colorado teachers, parents and education advocates are bombarding U.S. Sen. Cory Gardner’s office with phone calls, emails and tweets beseeching him to vote down President Donald Trump’s nominee for U.S. education secretary, Betsy DeVos.

Gardner, a Yuma Republican, expressed early support for the Michigan billionaire philanthropist. After meeting with DeVos in early January, Gardner said he looked “forward to working with her to ensure the next generation has access to a world-class education.”

Gardner’s office did not immediately respond Friday to a request for comment about whether the senator still supports DeVos since missteps in her confirmation hearing sparked widespread criticism that DeVos was unqualified.

However, Senate Republican leadership has said it has the votes to confirm DeVos, which would mean no additional Republicans plan to break party ranks beyond those who’ve already said they will.

In addition, Gardner has been one of the Senate’s strongest supporters of Trump, by at least one measure:

Senate Republicans early Friday pushed DeVos’s nomination over a procedural hurdle that clears the way for a final confirmation vote on Monday.

DeVos has used her personal wealth to advance school choice policies, including donating to politicians who support charter schools. The DeVos family contributed $46,800 to Gardner’s successful 2014 campaign, according to OpenSecret.org.

DeVos has become an unexpected lightning rod among Trump cabinet nominees. Critics, including some high-profile charter school advocates, have called on the Senate to not confirm DeVos, citing what they say is her dearth of knowledge about the education department’s role.

Two Republican senators have said they won’t support DeVos. Given that every Democratic senator is likely to reject her nomination, that would result in a 50-50 tie, putting the deciding vote in the hands of Vice President Mike Pence.

That’s why critics of DeVos in Colorado and around the nation are turning up the heat before the final confirmation vote on Monday. Those critics may hold out hope because Gardner was a vocal critic of Trump during the presidential campaign and this week called out Trump’s travel ban targeting Muslim countries, saying it is “overly broad,” “goes too far” and needs fixing.

“Bottom line: I have to be highly qualified to be a teacher, but she doesn’t have to be qualified in any sense of the word,” said Stephanie Rossi, a history teacher at Wheat Ridge High School who has emailed and called Gardner voicing her concern. “I’m troubled by the idea that anyone can just slip into the position to lead our complex public schools.”

Others joined the chorus.

A protest organized by the state’s largest teachers union, meanwhile, is scheduled for 9:30 a.m. Saturday at Gardner’s downtown Denver office.