Democratic lawmakers concluded their opening arguments in Republican President Donald Trump's impeachment trial in the U.S. Senate on Friday with a warning that he was a threat to democracy and would abuse his power again if he is not removed from office.

On the third and final day of opening statements, Democrats tried to cement their case that Trump abused his office by pressuring Kiev to investigate Joe Biden, former vice president and 2020 Democratic presidential contender, and then obstructed Congress' inquiry into the matter by barring witnesses and withholding documents.

"If it meets the standard of impeachable conduct, as we have proved, it doesn't matter whether you like him. It doesn't matter whether you dislike him," said Representative Adam Schiff, who made the final presentation for the prosecution in what is the third such proceeding in U.S. history.

"What matters is whether he is a danger to the country, because he will do it again. And none of us can have confidence, based on his record, that he will not do it again, because he is telling us every day that he will," Schiff said.

On Twitter, Trump dismissed the entire process and denied any wrongdoing. 

"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!"

The president's legal team will open its defense arguments on Saturday, and will have up to 24 hours over three days – Saturday, Monday and Tuesday – to make its case. Senate Majority Leader Mitch McConnell said Saturday's session would begin at 10 a.m. ET (1500 GMT) and run for several hours.

The 'wrongdoing'

The Democratic-led House of Representatives last month passed two articles of impeachment, setting the stage for a trial in the Republican-led Senate on whether to oust Trump before he seeks a second term in a November election.

Representative Hakeem Jeffries, another of the Democrats prosecuting the case, said Trump was "calling the shots" in soliciting Ukraine's interference in the 2020 U.S. election and others in the White House assisted him in trying to hide evidence of the misconduct when it was exposed.

"President Trump tried to cheat, he got caught and then he worked hard to cover it up," said Jeffries, who added there was a "toxic mess" in the White House that needed to be cleaned up on behalf of the American people.

Democrats have accused Trump of pressuring Ukrainian President Volodymyr Zelenskiy in a July 25 phone call to investigate Biden and his son Hunter, who served on the board of Ukrainian energy company Burisma. They say Trump temporarily withheld 391 million U.S. dollars in U.S. military aid to Ukraine as leverage for his demands.

Democrats also said Trump's refusal to comply with congressional subpoenas for documents and testimony in the impeachment inquiry was a textbook case of obstruction. They showed video clips of Trump's attacks on several witnesses in the inquiry and said it amounted to "witness intimidation."

"This is a determination by President Trump that he wants to be all-powerful. He does not have to respect the Congress. He does not have to respect the representatives of the people. Only his will goes. He is a dictator," Democratic Representative Jerrold Nadler said.

Trump's allies have argued his conduct does not rise to the level of an impeachable offense. The U.S. Constitution sets out the impeachment process for removing a president who commits "high crimes and misdemeanors."

"He has shown neither remorse nor acknowledgement of wrongdoing," said Democratic Representative Adam Schiff, who has spearheaded the prosecution of Trump in the trial. "Do you think if we do nothing, it's going to stop now?"

Schiff urged Republican senators to show "political courage" and agree to hear from more witnesses in the trial. Republicans voted along party lines earlier in the week to block Democratic requests for four administration witnesses, including former national security adviser John Bolton.

"I implore you, give America a fair trial. She's worth it," Schiff said.

Democrats this week have outlined their charges that Trump only grew interested in corruption in Ukraine when it appeared that Biden could become a serious political threat.

'Get rid of her'

ABC News said on Friday it had heard an audio recording from April 2018 in which Trump is heard saying he wants the dismissal of then-U.S. ambassador in Ukraine, Marie Yovanovitch.

"Get rid of her!" Trump said in the recording, according to ABC News.

If true, that would bolster Democrats' argument that Trump associates spent nearly a year trying to oust Yovanovitch because they saw her as an obstacle in their efforts to pressure Ukraine.

Trump fired Yovanovitch in May 2019. In an interview with Fox News, Trump said he had the right to fire ambassadors if he wished.

"I want to have ambassadors that are chosen by me," he said.

The president is expected to be acquitted in the Senate, where a two-thirds vote is required to convict and remove a president from office. No Republican senator has voiced any support for his ouster.

Senator Rick Scott told reporters on Friday that the Democrats had "done a poor job" prosecuting the case while his Republican colleague Senator Mike Braun said Democrats were trying to build a circumstantial case that was a "tough sell."

Democrats have focused their attention on a small group of Republican moderates they believe might support their efforts to bolster their case against Trump with the inclusion of new witness testimony and additional evidence.

"We know we'll never get Trump," Senate Democratic Leader Chuck Schumer said before the start of Friday's session. "But four Republican senators can step forward and say that we need witnesses and documents. And there are 12 or 13 who have never said a bad word about witnesses and documents."

What happens next?

Late January to early February, Democrats will push to hear from witnesses during the trial. If McConnell's resolution on initial trial rules is adopted, as expected, senators would likely vote some time after the trial has started on whether to introduce witness testimony sought by the Democrats.

On February 4, Trump is scheduled to deliver the annual State of the Union address to a joint session of Congress.

(With inputs from AFP, Reuters)

(Cover: House impeachment prosecutor Adam Schiff speaks during the impeachment trial against President Donald Trump in the Senate at the U.S. Capitol in Washington, January 24, 2020. /AP Photo)