- DeVos is still expected to be confirmed as secretary of education
- Vice President Mike Pence may be called upon to cast a tie-breaking vote in the Senate
"I simply cannot support her confirmation," Collins said on the Senate floor.
The stunning decision from a pair of veteran Republican lawmakers puts DeVos in a tenuous position as her final vote before the Senate nears, but top Republican aides are confident she will be confirmed.
If Republicans can maintain 50 votes in support of DeVos, then Vice President Mike Pence would become the tiebreaking vote to confirm her.
In order to help make this happen, Senate Majority Leader Mitch McConnell decided to move up the vote on DeVos ahead of the planned vote on Sen. Jeff Sessions for attorney general. Should Sessions leave the Senate before the DeVos vote, there would only be 49 Republicans committed to voting for her.
Questions emerged Tuesday after reports that DeVos appeared to have lifted key sections of her written answers from other authors, spurring the lead Democrat opposing her to say she was reviewing the potential plagiarism.
DeVos has been a major player in the conservative education reform movement for decades — but more often behind the scenes as a major political donor in state-level races than in the public eye.
DeVos' rocky performance at her confirmation hearing last month — which ended in part by her being lampooned on social media for suggesting schools keep guns for grizzly bears — led to a flood of emails and calls from opponents.