A federal judge on Monday allowed a lawsuit to proceed that challenges Alabama Attorney General Steve Marshall’s threat to prosecute anyone who facilitates abortions in states where the procedure is legal, slamming the attorney general’s office’s legal arguments in the process.

In their lawsuit filed in federal court in Montgomery, the Yellowhammer Fund, the West Alabama Women’s Center and other abortion rights advocates claim they want to help clients obtain abortions in legal states but have not done so because of Marshall’s threat, which they claim violates several constitution rights.

While U.S. District Court Judge Myron Thompson sided with Marshall on one of the attorney general’s claims, he denied Marshall’s motion to dismiss the suit on several grounds, including that it may violate the constitutional right to travel and freedom of expression.

“This case is simply about how a state may not prevent people within its borders from going to another state, and from assisting others in going to another state, to engage in lawful conduct there,” Thompson wrote. “Alabama can no more restrict people from going to, say, California to engage in what is lawful there than California can restrict people from coming to Alabama to do what is lawful here. In this sense, the case is not an ‘especially difficult call.’”

Marshall’s office’s interpretation of the right to travel goes against “common sense,” according to Thompson’s ruling.

“The attorney general’s characterization of the right to travel as merely a right to move physically between the States contravenes history, precedent, and common sense,” he wrote.

“Indeed, the Attorney General’s theory of the right to travel, which would allow each state to force its residents to carry its laws on their backs as they travel, ‘amount[s] to nothing more than the right to have the physical environment of the states of one’s choosing pass one’s eyes,’” Thompson continued. “Such a constrained conception of the right to travel would erode the privileges of national citizenship and is inconsistent with Constitution.”

Marshall’s office could not immediately be reached for comment.