Some of the Texas Democrats who left the state in protest of a redistricting bill were temporarily evacuated Wednesday from their Chicago-area hotel after a bomb threat, according to police and lawmakers.

Four hundred people were evacuated from the hotel where they were staying, but they were allowed to eventually return.

Gov. JB Pritzker vowed on late-night television to protect Texas House Democrats who fled to Illinois to try and stop the Republican-controlled state legislature from redrawing congressional district boundaries to the GOP’s advantage ahead of next year’s midterm election.