Warner: Trump dismissing Russian threat because he's "obsessed" with his own well-being

Virginia Democratic Senator Mark Warner is the vice chairman of the Senate Intelligence Committee -- the committee investigating Russian interference in the 2016 election. In his first interview since the Mueller hearings, Warner joins "CBS This Morning" from Washington to discuss why he still doesn't believe that impeachment proceedings should begin, his concerns about foreign election interference and the president's reaction to Mueller's testimony.