WASHINGTON — Democratic prosecutors sought to seal their case for President Donald Trump's conviction and removal on Friday, presenting evidence of his obstruction to the Senate trial.

House impeachment managers laid out the case that Trump's refusal to allow top officials to testify and to supply subpoenaed documents to the Ukraine investigation supported the second charge against him, obstruction of Congress.

Trump blocked the executive branch from responding to 71 specific requests for documents, including five subpoenas, related to his pressure on Kiev to help his 2020 reelection effort, the issue underlying the abuse of power charge, Democratic impeachment manager Val Deming told the Senate.

Trump also prevented 12 current and former administration officials, most of them subpoenaed, from testifying to the investigation, she said.

"President Trump's obstruction of the impeachment inquiry was categorical, indiscriminate and historically unprecedented," Demings said.

She said the Congress could not afford to allow Trump to reject its powers in such a wholesale manner.

"Executive power without any sort of restraint, without oversight, and without any checks and balances, is absolute power," she told the Senate hearing.

"And we know what has been said about absolute power. Absolute power corrupts, absolutely."

'Truth matters'

Deming opened the second part of the prosecution's arguments a day after lead House impeachment prosecutor Adam Schiff made the case for the first article of impeachment, including an impassioned plea to Senate jurors to convict and remove Trump.

He argued in particular that Trump's Ukraine scheme demonstrated the president was a threat to national security.

"You know, you can't trust this president to do what is right for this country. You can trust he will do what's right for Donald Trump," said Schiff, who is the chairman of the House Intelligence Committee.

"That is why, if you find him guilty, you must find that he should be removed."

"Because right matters. And truth matters. Otherwise we are lost."

On Twitter, Trump dismissed the entire process.

"The Do Nothing Democrats just keep repeating and repeating, over and over again, the same old 'stuff' on the Impeachment Hoax," he said.

"They ought to go back to work for our great American people!

Fight over subpoenas

The House impeachment managers were to close out their case late Friday, opening the way for Trump's defense to take the floor in the Senate for three days, Saturday, Monday and Tuesday, to argue for acquittal in only the third impeachment trial of a US president in history.

Trump's acquittal is virtually assured: The Republicans hold a 53-47 majority in the Senate, and a two-thirds supermajority is required for conviction and removal.

Democrats were hoping however to woo some Republicans to embrace their arguments that the Senate should subpoena four of the witnesses that Demings referred to, current and former White House officials with direct knowledge of Trump's Ukraine machinations.

There were hints that at least two or three Republicans were considering supporting the subpoenas, though none had committed.

But without four crossovers, analysts were predicting that Senate majority leader and key Trump defender Mitch McConnell would be able to bring the trial to a vote on the charges by late next week, and see Trump exculpated on a party-line vote by the weekend.

'They hate Trump'

If Democrats do gain support for subpoenas, Republican leaders threatened both to demand their own witnesses and call Democratic presidential hopeful Joe Biden and his son Hunter to testify, because their connections to Ukraine had been at the heart of Trump's scheme to tarnish his election rivals.

Trump and McConnell also suggested the president would claim executive privilege to reject the subpoenas, which would lead to a series of court challenges and ensure that the trial could go on for weeks more.

Neither party relishes that as the battle ahead of November elections picks up.

On Thursday the impeachment managers, the prosecution, mustered scores of videos, internal documents and extensive witness testimony to lay out their case that the US leader abused his powers, the first of two articles of impeachment against him.

In front of a national television audience, Schiff's prosecution team detailed how Trump flagrantly undertook last year to force Kiev to help him tarnish Biden.

Jay Sekulow, one of Trump's defense team, said they would open their reply to the prosecution Saturday by putting on an "affirmative case" that would "rebut and refute" the Democrats' arguments.

Republican Senator Jim Inhofe dismissed all the testimony so far as "hearsay".

"There wasn't a crime," he said. "These are not impeachable offenses."

"What is clear, with the House Democrats, is they just want to get rid of this guy. They hate Trump." — AFP