As Betsy DeVos’ nomination comes down to a final vote, Idaho’s Republican senators haven’t publicly pledged to support President Trump’s controversial education secretary nominee, Idaho EdNews reports. The non-answers come as DeVos faces a razor-thin Senate vote, and possibly a historic vote. The Senate hasn’t rejected a Cabinet nominee from its own party since 1925, writes EdNews reporter Kevin Richert.

As of Thursday, the conventional wisdom holds that DeVos will be confirmed after a 50-50 tie vote, with Vice President Mike Pence casting the deciding vote as president of the Senate. That math assumes that the Senate’s 48 Democrats will oppose DeVos, and none have signaled support for her. It also assumes that Republicans Susan Collins of Maine and Lisa Murkowski of Alaska vote against DeVos, as they have said they would. But the 50-50 scenario also assumes that the remaining Republicans hold ranks and vote to confirm DeVos.

The DeVos nomination has polarized not only the Senate, Richert reports, but education groups on both ends of the political spectrum. School choice advocates point to the billionaire activist’s longstanding and vocal support of vouchers and charter school programs in her native Michigan. Opponents have questioned DeVos’ support of public education. You can read Richert’s full report here.