The Republican-controlled U.S. Senate will hear opening arguments in President Donald Trump's impeachment trial on Wednesday, beginning up to six days of presentations on the question of whether Trump should be removed from office.
After battling into the early morning hours on Wednesday over the trial's rules, senators voted 53-47 to approve a hastily revised set of procedures put forth by Senate Majority Leader Mitch McConnell that allows up to 48 hours of opening arguments - 24 hours for each side - over six days.
Trump was impeached last month by the Democratic-controlled House of Representatives on charges of abuse of power and obstruction of Congress for pressuring Ukraine to investigate former Democratic Vice President Joe Biden, a political rival, and impeding the inquiry into the matter.
The president denies any wrongdoing.
The Senate trial, the third presidential impeachment trial in U.S. history, will resume at 1 p.m. (1800 GMT), the day after Democrats argued more witnesses and records were needed since the Trump administration had not complied with requests for documents and urged officials not to participate.
Democratic Representative Adam Schiff, who helped spearhead the House impeachment inquiry, said the evidence against Trump was "already overwhelming" but further witness testimony was necessary to show the full scope of the misconduct by the president and those around him.
"They insist that the president has done nothing wrong, but they refuse to allow the evidence and hearing from the witnesses ... and they lie, and lie and lie and lie," Representative Jerrold Nadler, one of the House's impeachment managers, said of the president's lawyers.
White House counsel Pat Cipollone fired back.
"Mr Nadler, you owe an apology to the president of the united states and his family," Cipollone said. "You owe an apology to the Senate. But most of all you owe an apology to the American people."
REMEMBER WHERE YOU ARE
That back-and-forth led Chief Justice John Roberts, who is presiding over the impeachment, to admonish both men.
"I do think those addressing the Senate should remember where they are," he said.
Republican senators have not ruled out the possibility of further testimony and evidence at some point after opening arguments and senators' questions, but they held firm with Trump to block Democratic requests for witnesses and evidence.
During a debate that finally wrapped up near 2 a.m. (0700 GMT) on Wednesday, 13 hours after it started, senators rejected on party lines, 53-47, four motions from Democratic leader Chuck Schumer to subpoena records and documents from the White House, the State Department, the Defense Department, and the Office of Management and Budget related to Trump's dealings with Ukraine.
By the same tally, senators also rejected requests for subpoenas seeking the testimony of acting White House Chief of Staff Mick Mulvaney, White House aide Robert Blair and White House budget official Michael Duffey.
Under the rules, lawyers for Trump could move early in the proceedings to ask senators to dismiss all charges, according to a senior Republican leadership aide, a motion that would likely fall short of the support needed to succeed.
Even if such a motion fails, Trump is almost certain to be acquitted by the Republican-majority 100-member chamber, where a two-thirds majority is needed to remove him from office.
But the impact of the trial on his re-election bid in November is far from clear.
The Senate trial is expected to continue six days a week, Monday through Saturday, until at least the end of January.
Trump and his legal team say there was no pressure and that the Democrats' case is based on hearsay. Cipollone described the Ukraine investigation as an illegal attempt to remove a democratically elected president and avert his re-election.
No president has ever been removed through impeachment, a mechanism the nation's founders - worried about a monarch on American soil - devised to oust a president for "treason, bribery or other high crimes and misdemeanors." One, Richard Nixon, resigned in the face of a looming impeachment.