US President Donald Trump’s looming impeachment trial in the Senate has reached an impasse as Republican and Democratic leaders in the upper chamber of Congress clash over impeachment rules.

The Democratic-controlled House of Representatives approved two articles of impeachment against the Republican president on Wednesday on charges of abuse of power and obstruction of Congress.

Trump became the third president in US history to be impeached, following the impeachments of former Presidents Bill Clinton and Andrew Johnson. Neither Johnson nor Clinton was convicted by the Senate.

Impeachment begins in the House. If the lower chamber of Congress approves articles of impeachment, a vote is then held in the Senate. A two-thirds majority vote would be needed in the Senate to remove the president from office.

Senate impeachment proceedings unfold in the form of a trial, with each side having the right to call witnesses and perform cross-examinations. With Republicans in control of the Senate, Trump’s acquittal in a January trial seems certain.

Senate Majority Leader Mitch McConnell, a Republican from Kentucky, said he is not opposed to calling witnesses for the Senate impeachment trial, but also indicated that he was not rushing to seek new testimony either.

“We haven’t ruled out witnesses,” McConnell said Monday in an interview with “Fox and Friends.” “We’ve said let’s handle this case just like we did with President [Bill] Clinton. Fair is fair.”

Senate Minority Leader Chuck Schumer, a Democrat from New York, responded that any trial without witnesses would be unacceptable, adding that he remained open to negotiating with McConnell.

“Let’s put it like this: If there are no documents and no witnesses, it will be very hard to come to an agreement,” Schumer told The Associated Press on Monday.

He told the AP that Democrats aren’t trying to delay but are simply asking for information directly relevant to the charges in the impeachment articles.

Schumer also demanded that the Senate, besides receiving testimony, also compel the Trump administration to turn over documents and emails relevant to the case.

In a letter Monday to all senators, Schumer rejected the Clinton model, arguing that the circumstances in the Trump trial are different from those of Clinton’s.

Clinton was impeached 21 years ago for lying under oath about having a sexual relationship with White House intern Monica Lewinsky. He was impeached after a lengthy independent counsel investigation in which witnesses had already testified numerous times under oath.

Source: Presstv