Santorum will be a guest on Wednesday's edition of the chat program.
"Santorum, who served as a U.S. Representative from Pennsylvania from 1991 to 1995 and later as U.S. Senator from the state from 1995 to 2007, is the author of the new book 'American Patriots: Answering the Call to Freedom,' which will be released the day before his 'Late Show' appearance," CBS said in a news release. "The book shares the true-life accounts of 25 unsung heroic men and women from the Revolutionary War era who fought and sacrificed to give future generations the freedoms enjoyed by the country today."
Millions of Getty images now available for free via embed tool
NBC reportedly holds celebs hostage to Jimmy Fallon's show