The Unites States Senate got stuck into President Donald Trump’s impeachment trial during a marathon opening session on Tuesday night in which Republicans and Democrats battled over rules of engagement.
Republicans abandoned plans to cram opening arguments into two days but solidly rejected Democrat demands for more witnesses to expose Trump's alleged offenses.
A session of nearly 13 hours began with a setback for Republican Senate leader Mitch McConnell and the president's legal team, exposing a crack in the GOP ranks and the growing political unease over the historic impeachment proceedings unfolding amid a watchful public in an election year.
But it ended at almost 2 am local time (8 am CET) Wednesday with Republicans easily approving the new trial rules largely on their terms.
McConnell opened the chamber promising a ``''fair, even-handed'' process and warned that the Senate would stay in session until his proposed rules package was adopted.
``The president's lawyers will finally receive a level playing field,`` the Kentucky Republican said, contrasting it with the House impeachment inquiry.
It is the third time in American history that Senators have to judge the president for "high crimes and misdemeanours" and decide whether he should be removed from office.
The US Senate opened around 19.00 CET with a debate on the rules of the proceedings.
Donald Trump is charged with abusing power by pressuring Ukraine to investigate his Democratic rival Joe Biden, and obstructing Congress by refusing to cooperate with its ensuing investigation.
No US president has ever been removed from office. This is very unlikely to happen this time, as the US Senate is controlled by the Republicans, Trump's party, and a two-thirds majority is needed for Trump to be convicted.
Trump himself will not be in Washington on Tuesday as he is attending the World Economic Forum in Davos, Switzerland. He has described the impeachment process as a "witch hunt". On Tuesday he said the impeachment trial is "disgraceful" and a "hoax".
The previous US presidents to be impeached, Andrew Johnson and Bill Clinton, were both acquitted by the Senate.
Allan J. Lichtman, a professor of history at the American University in Washington, told Euronews that the charges against Trump are "far more serious" than the charges in previous Senate trials in cases of impeachment.
"Trump is being charged with selling out our national security, with undermining our democracy, by shaking down a foreign power to help him cheat in the upcoming presidential election."
"I would be absolutely shocked if the trial was little more than a whitewash with the Republicans voting to acquit the president. But it's not a fair trial", Lichtman said.