The Senate Health, Education, Labor and Pensions Committee advanced the nomination of Betsy DeVos to lead the U.S. Department of Education Tuesday with a party-line vote of 12-11. But her confirmation by the full Senate does not appear to be a sure thing after two Republican committee members expressed doubts about voting for her confirmation on the Senate floor.

Maine Senator Susan Collins said DeVos's focus on charter schools as a philanthropist and activist raised questions about whether she understood her primary focus as education secretary would be to strengthen all public schools. And Collins voiced concerns about the nominee's commitment to enforcing the federal Individuals With Disabilities Education Act.

In addition, Alaska Senator Lisa Murkowski said, "This nomination is very difficult to me," citing comments from thousands of constituents concerned about DeVos's potential leadership of the department. Those Alaskans questioned DeVos's commitment to public education as well as whether she would uphold IDEA and federal civil rights laws in schools. Both Republican senators, however, said they would vote to advance the nomination out of deference to President Trump.

"I will show the same respect and same deference to President Trump's nominee as I did with President Obama's, and I will therefore vote to report Mrs. DeVos's nomination to the full Senate," Murkowski said. "But do know that she has not earned my full support."

The comments indicated an opening for DeVos's opponents, who held public demonstrations in the lead-up to the committee vote and have flooded the phones of senators' offices. Democrats already have indicated they will vote against DeVos as a bloc and are looking for Republican votes to stop her confirmation.

The committee hearing before the vote rehashed much of the ongoing debate between committee members over the qualifications of DeVos and the confirmation process.

Democrats, including ranking member Patty Murray of Washington, said they were frustrated not to have received more opportunities to question DeVos, who has no record in public policy or education outside of her political activities in support of charter and school voucher expansion. A former chairwoman of the Michigan Republican Party, she has supported mostly conservative political candidates across the country. And she has led efforts like the Alliance for School Choice, where she also served as chairwoman.

"We simply have not been given all of the information we need to make a decision as senators charged with robustly scrutinizing a president's nominee," Murray said.

Senator Lamar Alexander, a Tennessee Republican and the committee's chairman, said the committee had spent as much time questioning DeVos as it did President Obama's two education secretaries, Arne Duncan and John B. King Jr. He also pointed to more than 1,400 additional written questions submitted by senators before the committee vote.

"I believe she’s already the most questioned education secretary [nominee] in our history," Alexander said.

DeVos's responses to those written questions, which senators had received by Monday, didn't allay Democrats' concerns or provide clarification on many issues, senators said -- including some questions on higher education issues. Murray said that many of the responses were copied from other sources or simply reiterations of laws that are already on the books. A Washington Post report published before the committee's meeting Tuesday found that written answers to questions appeared to include sentences or phrases from sources that were used without attribution.

Massachusetts Senator Elizabeth Warren, a Democrat who has been a frequent critic of the for-profit college industry, said she was disturbed that DeVos had not committed to using the department's resources to hold such institutions accountable if they mislead students or commit fraud. DeVos also refused to commit to canceling the loans of students who were defrauded by for-profits, Warren said.

Activists, student loan borrowers and a handful of Democratic senators pushed the Obama administration in its final months to provide automatic group discharge to students who attended failed for-profit chains, including ITT Technical Institute and Corinthian Colleges, arguing that they would not receive that relief from the Trump administration.

"It is hard to imagine a candidate less qualified or more dangerous to be entrusted both with our country's education policy and with the country's trillion-dollar student loan program," Warren said.

North Carolina Republican Richard Burr said the Democrats' comments added up to a "character assassination" of DeVos and accused the minority party of deciding long ago to oppose her.

The contentiousness of the confirmation process for DeVos doesn't bode well for future bipartisan cooperation on the committee, some senators said. The manner in which the nomination was advanced, Murray said, could "dramatically impact our ability to work in good faith going forward."