In March, Secretary of State Marco Rubio stripped Turkish doctoral student Rümeysa Öztürk’s of her visa based on what a court later found was nothing more than her opinion piece critical of Israel.

Now, a bill introduced by the chair of the House Foreign Affairs Committee is ringing alarm bells for civil liberties advocates who say it would grant Rubio the power to revoke the passports of American citizens on similar grounds.

The provision, sponsored by Rep. Brian Mast, R-Fla., as part of a larger State Department reorganization, is set for a hearing Wednesday.

Mast’s legislation says that it takes aim at “terrorists and traffickers,” but critics say it could be used to deny American citizens the right to travel based solely on their speech. (The State Department said it doesn’t comment on pending legislation.)

Seth Stern, the director of advocacy at Freedom of the Press Foundation, said the bill would open the door to “thought policing at the hands of one individual.”

“Marco Rubio has claimed the power to designate people terrorist supporters based solely on what they think and say,” Stern said, “even if what they say doesn’t include a word about a terrorist organization or terrorism.”

Vague “Terrorist” Designations

Mast, for his part, has publicly voiced his support for “kicking terrorist sympathizers out of our country.” At the time, he was talking about deporting Mahmoud Khalil, a Palestinian green-card holder who the Trump administration detained and attempted to deport based on what critics of the move said were his pro-Palestine views.