More than four Republican senators will likely vote to block President Donald Trump’s emergency order on border security, as many are troubled by his move, Sen. Susan Collins, R-Maine, said Thursday.

“I haven’t taken a count, but I can tell you from talking with my colleagues that many are troubled, even those who are the strongest supporters of the president and his views on border security,” Collins told CNN’s “New Day.”

Collins, along with Sens. Rand Paul, R-Ky., Lisa Murkowski, R-Alaska, and Thom Tillis, R-N.C., have all said they’ll vote for the resolution opposing Trump’s emergency order.

Collins said Thursday there is no doubt stronger border security is needed, and the nation’s immigration system is broken, but that is an “entirely different” from the constitutional authority for Congress to appropriate funds, and that is her main concern.

“I don’t see this debate about being whether you are for the wall or against the wall, whether you like President Trump or you dislike President Trump,” Collins said. “I see this as a very important constitutional debate where Congress must step up, protect its institutional prerogatives and defend its role under Article I of the Constitution.”

She said she also disagrees with Trump, who tweeted Republicans are voting on border security, not a constitutional matter.

“What this debate is about is whether the president of the United States can take billions of dollars that have been appropriated that he’s signed into law and then repurpose them for other projects,” Collins said.