Michael Cohen is involved in two separate investigations, both of which are connected to President Trump, and both of which resulted in guilty pleas.
Cohen, President Trump’s personal/business lawyer, admitted to lying to Congress about negotiations for Trump on a development project Trump was trying to get permission to build in Moscow. Cohen said the negotiations lasted longer into the campaign than anyone thought, and, he said, Trump knew about them.
Cohen also said he broke campaign finance laws by paying off two women who might have cast a bad light on Trump as he was running for president. Campaign finance laws are in place in order to provide transparency during the election progress.
Cohen said he made payments at the direction of the president. This case was initially referred by Mueller but is being run by New York state investigators.
These two guilty pleas by Cohen—one, that indicates a connection between then-candidate Trump and Moscow that Trump has lied about; the second, that indicates an illegal campaign contribution, that Trump has also lied about—have brought the impeachment discussion to the forefront.
Only two Presidents have been impeached (Andrew Johnson, in 1868, and Bill Clinton, in 1998 ). Richard Nixon resigned in 1974 before facing impeachment.