Former FBI agent offers inside look at Trump's relationship with James Comey

Josh Campbell served as special assistant to former FBI Director James Comey, and was with Comey the day President Trump fired him. The former special agent details his experiences in a new book, which provides a behind-the-scenes look at the beginnings of the FBI investigation into Russian election meddling. It's called, "Crossfire Hurricane: Inside Donald Trump's War on the FBI." Campbell joins “CBS This Morning” to discuss his new book.