Still, Thomas’ views can be so far from his fellow justices that neither Roberts nor Chief Justice William Rehnquist before him have assigned Thomas big, landmark opinions on the belief that he won’t be able to keep together the votes of his colleagues, said Ralph Rossum, the author of a book on Thomas. Instead, Thomas often writes separately, speaking only for himself. Some critics dismiss those solo opinions as uninfluential, but Rossum disagrees.

“He stakes out a position more forthrightly or vigorously than other justices are willing to go, but they’re kind of sucked along in his wake,” Rossum said, adding that, like a magnet, “Thomas drags the court in his direction. They may not go as far as he goes, but they go further than they would have otherwise.”

Some of the areas of law where, over time, Thomas has pulled the court closer to his positions include voting rights, campaign finance, and the Second Amendment, Robin and Rossum said.