Last week, public impeachment hearings of President Trump began in the House Intelligence Committee – and pretty much everyone who does not appear on Fox News or the Rush Limbaugh Radio Show proclaimed the proceedings to be “historic”This week Katie and Joe discuss the history of impeachment with presidential historian Professor Douglas Brinkley.Professor Brinkley is is a celebrated historian and the award-winning author, co-author or editor of more than 30 books, most of these works focus on American presidents or people we know because of presidents. He is the Katharine Sarnoff Brown Chair of humanities and professor of history at Rice University. He is a CNN presidential historian and a contributing editor at Vanity Fair.