A controversy over Fox News host Tucker Carlson’s texts and emails has revived Republican interest in curtailing the National Security Agency’s surveillance program, an issue that has often divided the party between libertarians and national security hawks.

Fifteen House Republicans, led by Reps. Louie Gohmert of Texas and Bill Posey of Florida, sent the NSA a letter on Tuesday, demanding explanations of its surveillance practices and how a U.S. citizen’s communications might lawfully be ensnared in its spying on foreign nationals.