In the last few decades, impeachment has become a political weapon. Now we find ourselves in the middle of an impeachment inquiry, looking to history to understand how, why, and even if Donald Trump should be impeached.

Laying out the secretive, months-long effort by administration officials to pressure the Ukrainian government to announce investigations of former Vice President Joseph Biden and alleged Ukrainian interference in the 2016 U.S. presidential election.

Jake Tapper speaks to scholars, historians, and philosophers about how the president's statements foster a culture of mistrust, leading Americans to question the integrity of scientists, economists, world figures, and the media.