On Thursday, POLITICO reported that Sen. Lamar Alexander (R-TN) delivered a message on the Senate floor on behalf of some of his colleagues, warning that if President Donald Trump tries to implement his plan to build a border wall under the guise of a national emergency, he could face defections within his party:

In a much-anticipated floor speech, the retiring senator declined to state whether he will become the deciding vote to block the president’s maneuver. But he signaled broad opposition to the emergency declaration and sought to convince Trump that he has other ways to collect $5.7 billion for the border wall — the precise amount of money he demanded during the government shutdown fight.

“He’s got sufficient funding without a national emergency, he can build a wall and avoid a dangerous precedent,” Alexander told reporters afterward, referring to billions from a drug forfeiture fund and anti-drug smuggling money at the Defense Department. “That would change the voting situation if he we were to agree to do that.”

This week, the House passed a resolution 245-182 to cancel Trump’s emergency declaration under the National Emergencies Act, with thirteen Republicans breaking ranks to join the Democrats. Under the rules, the Senate is now required to take up the resolution within 18 days of the House vote.

Three Republicans have so far stated they will vote in favor of the resolution: Sens. Susan Collins (R-ME), Lisa Murkowski (R-AK), and Thom Tillis (R-NC). Only one more Republican vote would be necessary to pass it.