https://www.yahoo.com/news/impeachment-decoded-look-remove-u-president-121136277.html

Trump has denied collusion and obstruction. He has called Mueller's investigation a "witch hunt." Russia has denied e******n i**********e.
GRAPHIC: Impeaching a U.S. president - https://tmsnrt.rs/2ECfGoE
ON WHAT GROUNDS CAN A PRESIDENT BE IMPEACHED?

Under the Constitution, the president, vice president and "all civil officers of the United States" can be removed from office for "treason, bribery, or other high crimes and misdemeanors," without being more specific.
Only two U.S. presidents have ever been impeached: Andrew Johnson in 1868 in the tumultuous aftermath of the American Civil War; and Bill Clinton in 1998 over issues including his relationship with a White House intern named Monica Lewinsky. Both times, the House approved formal charges, only to have the Senate fail to convict and remove.

The House Judiciary Committee in 1974 v**ed to recommend impeachment accusing another president, Richard Nixon, of planning to obstruct an investigation in the Watergate scandal. Before the full House could v**e on impeachment, Nixon became the only U.S. president ever to resign.
WHAT IS THE PARTY BREAKDOWN IN CONGRESS?

There currently are 235 Democrats, 197 Republicans and three vacancies in the House. As a result, the Democratic majority could v**e to impeach Trump without any Republican v**es. In 1998, when Republicans controlled the House, the chamber v**ed largely along party lines to impeach Clinton, a Democrat.

Currently, the Senate is made up of 53 Republicans, 45 Democrats and two independents who usually align with Democrats. With conviction and removal of a president requiring 67 v**es, that means at least 20 Republicans would have to v**e against Trump if all the Democrats and the two independents remained unified in order to remove him from office.

The House Judiciary Committee likely would hold hearings on potential charges against Trump before the full House considers impeachment. If articles of impeachment are approved by the House, U.S. Chief Justice John Roberts would preside over the trial in the Senate, with selected House lawmakers acting as the prosecutors presenting the case on the Senate floor before senators v**e on whether to convict.
WHO BECOMES PRESIDENT IF TRUMP IS REMOVED?

A Senate conviction removing Trump from office would automatically elevate Vice President Mike Pence to become president, filling out Trump's term, which ends on Jan. 20, 2021.
Current U.S. Justice Department policy, first adopted in 1973 and reaffirmed in 2000, opposes the idea of bringing criminal charges against a sitting president, concluding that to do so would violate the separation of powers set out in the Constitution for the three branches of the U.S. government: executive, legislative and judicial.

The Constitution allows that once a president is removed, separate criminal charges could be pursued in court that could result in conviction and punishment potentially including imprisonment.
(Reporting by Richard Cowan; Editing by Will Dunham)