Three constitutional experts on Wednesday bolstered Democrats' efforts to impeach Donald Trump by saying the president's actions seeking foreign interference in US elections are grounds for removal, as the inquiry kicked into a new phase in Congress.
But reflecting the Washington political divide, a fourth expert strongly dissented, saying there was "woefully inadequate" evidence that Trump committed high crimes and misdemeanors necessary for impeachment.
Democrats have made a forceful case that Trump should be removed from office for abusing his powers by pressuring Ukraine for dirt on an election rival, arguing that the Founding Fathers had a remedy - impeachment - for such wrongdoing.
In a theatrical, contentious hearing of the House Judiciary Committee - now tasked with weighing impeachment charges against the president - lawmakers listened to damning testimony from constitutional law professors who said Trump's conduct rises to that level.
"We three are unanimous," jurisprudence professor Michael Gerhart of the University of North Carolina stated, referring to fellow witnesses Pamela Karlan, a Stanford Law School professor, and professor Noah Feldman of Harvard Law School.
Americans tuning in to the live broadcast witnessed heated clashes between Democrats and Republican Trump loyalists on the panel, who repeatedly forced procedural votes to help stall the process.
The new phase of impeachment began a day after a congressional report on the high-stakes inquiry detailed "overwhelming" evidence of abuse of power and obstruction by the president.
The report mapped out a months-long scheme by Trump, his personal lawyer Rudy Giuliani, senior diplomats and White House staffers to pressure Ukraine's president into investigating Joe Biden, the current favorite to win the Democratic nomination in 2020.
Trump "was willing to compromise our security and his office for personal, political gain" by "directly and explicitly" inviting foreign interference in US elections in 2016 and again in his 2020 reelection effort, the Judiciary Committee chair, Jerry Nadler, said in his opening statement.
One of the scholars told Wednesday's hearing Trump had perpetrated one of the gravest political transgressions in US history.
"The president's serious misconduct, including bribery, soliciting a personal favor from a foreign leader in exchange for his exercise of power, and obstructing justice and Congress are worse than the misconduct of any prior president," said Gerhart.
"If Congress fails to impeach here, then the impeachment process has lost all meaning, and, along with that, our Constitution's carefully crafted safeguards against the establishment of a king on American soil."
White House spokeswoman Stephanie Grisham hit back, claiming that "3 of 4 'experts' in this sham hearing have known biases" against Trump.
The fourth expert, professor Jonathan Turley of George Washington University Law School -- the only one chosen by Republicans - had a very different assessment.
Turley, who also testified during Bill Clinton's impeachment in 1998, argued there is "no evidence" that Trump "acted with the corrupt intent required for obstruction of justice."
Disclosing that he himself had voted against Trump in 2016, Turley said opposition to the president was "irrelevant" to the constitutional questions before Congress.
"One can oppose President Trump's policies or actions but still conclude that the current legal case for impeachment is not just woefully inadequate, but in some respects, dangerous."
The president himself, in London for a Nato summit, lambasted his opponents for proceeding with impeachment hearings during his trip.
"What they are doing is a very bad thing for our country," Trump said. "It's a joke."
Congressman Doug Collins, the Judiciary panel's top Republican, piled on, calling the inquiry a "railroad job" wasting the American public's time.
Collins faced a scolding, however, from one of the professors when he insinuated that they have not followed the twists and turns of the impeachment process.
"I am insulted by the suggestion that as a law professor I don't care about those facts," Karlan said.
Karlan also squarely asserted that Trump's alleged effort to withhold military aid until Ukraine committed to investigating Biden was grounds for removal - even though the aid was eventually delivered.
"Soliciting itself is the impeachable offense," she said.
The House Intelligence Committee report released Tuesday is expected to form the basis for Judiciary to draw up formal charges - articles of impeachment - that could include bribery, abuse of power, obstruction and contempt of Congress.
Democrats reportedly aim to have the articles presented for a vote to the entire House of Representatives by late December.
If they pass as expected, Trump would then stand trial for removal in the Republican-controlled Senate, where he is likely to be exonerated.