Two Republican senators voted Tuesday against President Donald Trump’s secretary of education nominee, Betsy DeVos, forcing Vice President Mike Pence to cast a historic vote to break the tie to confirm her.

Republican Sens. Lisa Murkowski of Alaska and Susan Collins of Maine sided with every Democrat and two independent senators to oppose DeVos. Pence then cast the deciding vote, which marks the first time a vice president has had to break a tie regarding a Cabinet nomination.

Murkowski and Collins announced their opposition to DeVos ahead of the vote on the grounds she is not qualified to be the education secretary. “I simply cannot support her confirmation,” Collins said on the Senate floor last week.

DeVos has been criticized for showing a lack of depth of knowledge of the education system in her confirmation hearings, but is primarily opposed by Democrats because of her standing as a wealthy conservative who is pro-school choice. Murkowski and Collins were accused by some conservatives of voting no because of influence from teachers unions in their districts who are opposed to DeVos.

Murkowski was just re-elected to another six years in the Senate, and Collins is not up for re-election until 2020.

This article was originally published by The Daily Caller News Foundation.