Democrats told President Donald Trump's impeachment trial Thursday that he openly and dangerously abused his powers to gain political advantage.

House impeachment managers laid out the evidence for the first of two articles of impeachment against the US leader in the second day of arguments, methodically dismantling Republican claims that Trump did nothing wrong in soliciting electoral help from Ukraine last year.

US President Donald Trump
US President Donald Trump fired off a volley of tweets criticizing his Senate impeachment trial. Photo: AFP / SAUL LOEB

As the 100 senators sat as jurors, the prosecutors played old videos in which two of the president's closest defenders said that abuse of power is a clear impeachable offense, puncturing a key White House argument that the US constitution requires a specific crime to remove a president.

"President Trump used the powers of his office to solicit a foreign nation to interfere in our elections for his own personal benefit," House Judiciary Committee Chair Jerry Nadler, one of the impeachment managers, told the chamber.

"Since President George Washington took office in 1789, no president has abused his power in this way," Nadler said.

Trump's lawyer
Jay Sekulow, a lawyer for Donald Trump, speaks to reporters at the president's impeachment trial. Photo: AFP / Mandel NGAN

"The president has repeatedly, flagrantly, violated his oath... The president's conduct is wrong. It is illegal. And it is dangerous."

Democrats were planning to spend Thursday's trial session arguing their case on the first impeachment charge, and take on the second -- obstruction of Congress -- on Friday.

Trump impeachment trial
Members of the Democratic prosecution and Trump's defense teams in the impeachment trial in the US Senate. Photo: AFP / Gal ROMA

That will be the prosecution's final day before Trump's defense takes the Senate podium from Saturday to Tuesday.

Democrats are hoping to break Republican unity and vote with them to remove the president -- an uphill battle given the Republicans' 53-47 majority in the Senate and Trump's ability to keep his party in line.

They are also hoping that, ten months before national elections, the nationally televised hearings will sway voters dubious of impeachment that Trump is unworthy of reelection.

Trump impeachment trial
IMAGESDemocrats begin presenting their opening arguments at the historic impeachment trial of US President Donald Trump. Lead House impeachment manager, Adam Schiff, takes the podium on the floor of the Senate to make the case against President Trump. Democrats have 24 hours over the next three days to present their case. Photo: Senate Pool /

After reports that many republicans were absent from much of Wednesday's session, House Chaplain Barry Black opened the hearing Thursday with a invocation call to listen.

"Lord, help them remember that listening is often more than hearing," he said. "It can be an empathetic attentiveness that builds bridges and unity."

Adam Schiff
Adam Schiff (C) is the chief House prosecutor at the Senate impeachment trial of President Donald Trump. Photo: GETTY IMAGES / CHIP SOMODEVILLA

At the White House, Trump unleashed a barrage of tweets attacking the process as "loaded with lies and misrepresentations."

He attacked Adam Schiff, the chief House prosecutor who led the opening arguments Tuesday, in starkly personal terms, calling him "Shifty Schiff," and retweeted criticism of the California lawmaker made by White House supporters to Fox News.

Nadler, a longtime adversary of the New York real estate tycoon, challenged a key tenet of the president's legal defense: that neither of the charges against him, abuse of power and obstruction of Congress, constituted a criminal charge matching the US Constitution's stipulation for "high crimes and misdemeanors" for impeachment.

He reached deep into English law for the origins of the phrase, as defining "offenses against the nation itself."

And he cited the writings of the men who authored the US constitution in the 1780s, the "framers" much hallowed in US history.

"The framers were not naive. They knew that power corrupts," Nadler said.

"Simply stated, impeachment is the constitution's final answer to a president who mistakes himself for a king."

Underscoring the point, he taunted Republicans by playing late 1990s videos of Trump's most steadfast Senate defender, Lindsey Graham, and a member of his legal team, storied criminal defense lawyer Alan Dershowitz, both saying that abuse of power was indeed an impeachable charge.

Following Nadler, another impeachment manager, Sylvia Garcia, methodically detailed how Trump's using the pressure of aid to get dirt from Ukraine on his potential 2020 reelection rival Joe Biden was done for purely political reasons, She insisted there was no evidence backing Trump's claims that he was legitimately probing corruption.

She played videos of Trump officials, including the head of the FBI, dismissing his claim that Ukraine helped Democrats in the 2016 election.

"Where did this theory come from? You guessed it: the Russians," Garcia said in the nationally televised hearing.

"What is so dangerous is that President Trump is helping them perpetuate this -- our own president is helping our adversary attack our processes."

And, in a surprise, Garcia picked through the connections that former vice president Biden and his son Hunter had with Ukraine -- the son had served on the board of a leading Ukrainian energy firm -- to demonstrate there were no grounds for any allegations of corruption against them.

Copyright AFP. All rights reserved.