President Donald Trump addressed the nation Tuesday in a speech on immigration, his highly-publicized claims of a “crisis” on the southern border, and his demand to fulfill a campaign promise for a wall between the U.S. and Mexico that has led to a weeks-long partial government shutdown.

Trump was expected by some to use the power of the executive branch to declare a “national emergency” in order to bypass congress and get started on building his border wall. Trump didn’t make such a declaration, but he still could — so what would that mean moving forward, especially since Trump is demanding more than $5 billion to pay for the project?

According to ACLU Massachusetts Executive Director Carol Rose, Trump will see countless legal challenges if he does make such a declaration.

“He can try, but he’s going to be challenged in court by the ACLU and by about a million other groups,” Rose said during an interview with Boston Public Radio Tuesday. “First of all, there isn’t a national emergency, except the one that the Trump administration itself has created.”

According to Rose, Trump’s declaration — without a threat from foreign military or any outside forces — is a “state of emergency” created by the Trump administration internally “by separating children and families at the border and having these children who are dying in immigration custody along the border, separating children from their mothers and fathers … this kind of stuff, that’s the real emergency,” she said.

“Through different circumstances, there are still children and parents being separated,” Rose said, referencing the thousands of children separated from their families at the southern border, “but they still haven’t reunited the ones that their original policy separated.”

According to Rose, Trump could commandeer resources to “do his bidding” and construct a border wall, but not without a fight.

“I think this is clearly going to be declared unconstitutional,” Rose said. “We cannot commandeer our military to do domestic work.”