Betsy DeVos, the Michigan philanthropist nominated to be the next U.S. education secretary, won the votes she needed in the Senate’s education committee on Tuesday. She now faces a confirmation vote by the full Senate.

But it’s still not completely clear that DeVos will prevail, after two Republican senators raised the possibility that they won’t support her. If Senate Democrats all vote to oppose DeVos, three Republicans voting with them would derail the nomination.

During the committee hearing, Sen. Lisa Murkowski of Alaska and Sen. Susan Collins of Maine both said they were not yet committed to supporting DeVos in a final vote.

Murkowski’s indicated that the outpouring of protest from constituents has had an effect. “I absolutely believe that Betsy DeVos cares deeply for kids,” she said. But, she said later, “I have to acknowledge the thousands, the thousands, of Alaskans who shared their concerns with me about Mrs. DeVos as secretary of education. They have come to my office here in Washington, in Alaska, on the phones, in petitions. And their concerns center on Mrs. DeVos’s lack of experience in public education and the lack of knowledge she portrayed at her confirmation hearing.”

Here is Collins’s full explanation: