"I support the lawsuit that has been brought and I believe this was an unwise decision by the president," Collins told a Maine TV station in an interview that aired on Tuesday evening. 
Sixteen states, including Maine, have signed on to a lawsuit challenging Trump's emergency declaration. The lawsuit argues that Trump "used the pretext of a manufactured ‘crisis’ of unlawful immigration to declare a national emergency and redirect federal dollars ... toward building a wall."

Collins added that she she wouldn't be surprised if a court ruled against the administration. 
"I would not be at all surprised if the courts find that the president's action is contrary to the separation of powers," she said. "I don't think under the Constitution that he can unilaterally decide to move these funds, which were legally appropriated, from one project to another." 
Trump announced on Friday that he would declare a national emergency after Congress passed a bill that included $1.375 billion for fencing along the border — well below the $5.7 billion requested by the president. 
During a rambling press conference from the Rose Garden, Trump predicted that the 9th Circuit would rule against his emergency declaration, but that he was prepared to take the fight to the Supreme Court where he hoped he would get a "fair shake." 
Collins is one of several GOP senators who have voiced concerns about, or opposition to, Trump's decision to declare a national emergency. Democrats could force a vote on a resolution of disapproval to block the declaration; Collins has not said how she would vote on such a measure.
"I am strongly opposed to the president invoking his national emergency powers. I don't believe that's what the law was intended to cover," she told the Maine TV station, adding that the president's move is of "dubious constitutionality."