Explainer: How impeachment works and why Trump is unlikely to be removed

FILE PHOTO: U.S. President Donald Trump boards Air Force One at Joint Base Andrews in Maryland

By Jan Wolfe

WASHINGTON (Reuters) - The Democratic-controlled U.S. House of Representatives is expected to impeach Republican President Donald Trump this week for pressuring Ukraine to investigate a potential rival in the 2020 presidential election.

What happens next and why is Trump unlikely to be removedfrom office?

WHY IMPEACHMENT?

The founders of the United States feared presidents abusingtheir powers, so they included in the Constitution a process forremoving one from office.

The president, under the Constitution, can be removed fromoffice for "Treason, Bribery, or other high Crimes andMisdemeanors."

High crimes and misdemeanors have historically encompassedcorruption and abuses of the public trust, as opposed to indictable violations of criminal statutes.

Former President Gerald Ford, while in Congress, famouslysaid: "An impeachable offense is whatever a majority of theHouse of Representatives considers it to be at a given moment inhistory."

No president has ever been removed as a direct result ofimpeachment. One, Richard Nixon, resigned before he couldbe removed. Two, Andrew Johnson and Bill Clinton, were impeachedby the House but not convicted by the Senate.

HOW DOES IT WORK?

Impeachment begins in the House, the lower chamber, whichdebates and votes on whether to bring charges against thepresident via approval of an impeachment resolution, or"articles of impeachment," by a simple majority of the body'smembers.

The Constitution gives House leaders wide latitude indeciding how to conduct impeachment proceedings, legal expertssaid.

The House Intelligence Committee investigated whether Trump abused his power to pressure Ukraine to open probes that would benefit him politically, holding weeks of closed-door testimony and televised hearings before issuing a formal evidence report.

The House Judiciary Committee used the report to draft formal charges and voted 23-17 along party lines to approve charges against Trump of abuse of power and obstructing House Democrats' attempts to investigate him for it.

If the full House approves articles of impeachment as expected there will be a trial in the Senate.

House members act as the prosecutors; the senators as jurors; the chief justice of the United States presides. Historically, the president has been allowed to have defense lawyers call witnesses and request documents.

CAN THE SENATE REFUSE TO HOLD A TRIAL?

There is debate about whether the Constitution requires aSenate trial. But Senate rules in effect require a trial, andSenate Majority Leader Mitch McConnell has publicly stated thathe will allow one to proceed.

Republicans could seek to amend those rules, but such a moveis politically risky and considered unlikely, legal expertssaid.

WHAT'S THE PARTY BREAKDOWN IN CONGRESS?

Democrats control the House. The House comprises 431 membersat present, 233 of whom are Democrats. As a result, theDemocrats could impeach the Republican Trump with no Republicansupport.

In 1998, when Republicans had a House majority, the chambervoted largely along party lines to impeach Clinton, a Democrat.

The Senate now has 53 Republicans, 45 Democrats and twoindependents who usually vote with the Democrats. Conviction andremoval of a president would require a two-thirds majority. Republicans are seen as highly unlikely to convict the leader of their party. Should all 100 senators vote, at least 20 Republicans and all the Democrats and independents would have to vote against him.

WHO BECOMES PRESIDENT IF TRUMP IS REMOVED?

In the unlikely event the Senate convicted Trump, VicePresident Mike Pence would become president for the remainder ofTrump's term, which ends on Jan. 20, 2021.

(Reporting by Jan Wolfe; Editing by Ross Colvin and Grant McCool)