Republicans and Democrats sparred Wednesday over whether there has been enough investigation to support an impeachment inquiry if the first day of hearings before the House Judiciary Committee, which will be responsible for drafting articles of impeachment.

The hearing, which featured four professors, all experts on constitutional law and the history of impeachment, came a day after House Democrats released their report, detailing what they described President Trump’s abuse of the power of his office for personal political gain.

Trump maintained Twitter silence during the hearing as he headed back to the United States following the two-day NATO summit in London, during which he answered numerous questions on the impeachment proceedings, lashing out at Democrats, questioning their “love of our country” and calling the impeachment report “a joke.”

“Never before has a president engaged in a course of conduct that included all of the acts that most concerned the framers [of the Constitution],” Chairman Jerrold Nadler, D-N.Y., said during his opening statement.

He added: “When we apply the Constitution to those facts, if it is true that President Trump has committed an impeachable offense, or multiple impeachable offenses, then we must move swiftly to do our duty and charge him accordingly.”

“You just don’t like the guy. You’ve didn’t like him since November of 2016,” the ranking Republican, Rep. Doug Collins of georgia railed when it was his turn to speak.

Collins said the hearings were unnecessary because Democrats are “already drafting articles of impeachment.”

Republicans repeatedly attempted to stop the proceedings, seeking points of order and other motions aimed at suspending the hearing.

Professors Noah Feldman of Harvard Law School, Michael Gerhardt of north Carolina School of Law, Pamela S. Karlan of Stanford Law School and Jonathan Turley of George Washington University Law School gave lawmakers perspective on whether President Trump’s actions involving Ukraine rise to the level of impeachable offenses.

Three of them – Feldman, Gerhardt and Karlan – testified evidence gathered so far prove Trump abused his office and attempted to subvert the election process by soliciting help from a foreign government. Turley said evidence is lacking and the current inquiry runs the risks of lowering the standard for impeachment, noting the cases brought against Richard Nixon and Bill Clinton dealt with actual crimes under the law while the allegations against Trump do not have a statutory basis.

Nadler asked Feldman what the framers would have made of Trump’s effort to get Ukraine to investigate former Vice President Joe Biden, his son, hunter, and a debunked conspiracy theory promoted by Russia.

“Exactly the kind of abuse of office, high crime and misdemeanor that they were worried about,” Feldman said.