Diana Degette, the member presiding over the U.S. House of Representatives, pounds the gavel to open the session to discuss rules ahead of a vote on two articles of impeachment against U.S. President Donald Trump on Capitol Hill in Washington. File photo: House TV via REUTERS.

WASHINGTON – The House of Representatives began debate on Wednesday in what one lawmaker called a “democracy-defining moment” ahead of historic votes on two charges against President Donald Trump accusing him of abusing his power and obstructing Congress that would make him only the third U.S. president to be impeached.

The votes in the Democratic-controlled House are expected to fall almost entirely along party lines, underscoring the deep divide in Congress over the Republican president’s conduct and the larger political schism within the United States.

Impeachment is an extraordinary check on presidential power spelled out in the U.S. Constitution enabling Congress to remove presidents who commit “high crimes and misdemeanors.”

The vote, expected in the early evening, would set the stage for a trial expected next month in the U.S. Senate on whether to convict Trump and remove him from office. While the House twice previously has voted to impeach presidents – Bill Clinton in 1998 and Andrew Johnson in 1868 – no president has ever been removed from office via impeachment.

The Senate is controlled by Trump’s fellow Republicans, who have shown little interest in ousting him. During the trial, House members would act as prosecutors as the senators as jurors.