Republican senator who could be deciding vote in national emergency disapproval calls Trump's actions 'unnecessary and unwise'

A Republican senator who could be the deciding vote in a disapproval of President Trump's national emergency declaration says the president's actions present a "constitutional crisis."

Sen. Lamar Alexander (R-Tenn.) on Thursday said that while he supports "what the president wanted to do on border security," he does "not support the way he has been advised to do it," per BuzzFeed News. "It is unnecessary and unwise to turn a border crisis into a constitutional crisis," he said. Alexander also set forth an argument that Trump can fund the wall with "the authority he already has" without a national emergency.

The House previously passed a resolution to block Trump's declaration of a national emergency on the southern border, leaving all eyes on the Senate to do the same. With Sens. Susan Collins (R-Maine), Lisa Murkowski (R-Alaska) and Thom Tillis (R-N.C.) on board, only one more Republican needs to join the Democrats for the Senate to pass the resolution.

It sounds like Alexander could be that Republican, although he didn't actually say on Thursday whether he'll vote for the resolution. In fact, The Washington Post's Erica Werner reports he refused to answer a question about how he'd vote, saying he didn't want to get into hypotheticals. Senate Majority Leader Mitch McConnell (R-Ky.) says a vote on the resolution will take place before March 18, per NPR.

Of course, if the Senate does pass this resolution of disapproval, Trump will likely just veto it. A supermajority would be required to override Trump's veto, which the Senate almost certainly does not have. This would be the first veto of the Trump administration.