The impeachment inquiry moved to the House Judiciary Committee on Wednesday with a panel of constitutional scholars tackling the million dollar question in the debate: Do President Donald Trump's actions warrant impeachment under the Constitution?
Three of the witnesses were lawyers handpicked by the Democratic majority: Pamela Khan, a professor at Stanford Law School; Michael Gerhardt a professor at the University of North Carolina School of Law; and Noah Feldman, a professor at Harvard Law School.
The lone Republican-picked witness was Jonathan Turley, a professor at the George Washington University Law School.
Here's what you need to know about the hearing:
The Democratic-picked lawyers say Trump is what the framers had in mind with impeachment
Among the three Democratic-picked lawyers, there was no doubt: Trump, they testified, abused his power in office by pressuring Ukraine to investigate his political rival. And soliciting a foreign power for personal and political gain was exactly what the framers had in mind when they tucked impeachment powers into the Constitution, they said. If left unchecked, the president could continue to invite foreign powers to help his upcoming election, the lawyers argued.
"We three are unanimous," Gehardt said, when they were asked if Trump's actions amount to a "high crime and misdemeanor," as identified in the Constitution.
"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," Gerhardt said in his opening statement. "No one, not even the president, is beyond the reach of our Constitution and our laws."
The most colorful examples came from Karlan, who described being so riveted by witness testimony in the impeachment hearings that she opted for a mail-order turkey this Thanksgiving so that she could spend her time combing through the details. One "chilling line" by Ambassador Gordon Sondland's testimony, she said, was that Trump didn't need Ukraine to pursue a corruption case against Democrat Joe Biden, but rather just announce one.
"This was not about whether (former) Vice President Biden actually committed corruption or not. This was about injuring somebody who the president thinks of as a particularly hard opponent," she said.
Karlan also compared Trump's actions with Ukraine to a president withholding disaster aid for a state.
"Imagine living in a part of Louisiana or Texas that's prone to devastating hurricanes and flooding," Karlan told the panel.
"What would you think if you lived there and your governor asked for a meeting with the president to discuss getting disaster aid that Congress has provided for? What would you think if that president said, I would like you to do us a favor. I'll meet with you, and I'll send the disaster relief once you brand my opponent a criminal."
The GOP-picked lawyer had a somewhat surprising argument against impeachment
Turley, who testified during President Bill Clinton's impeachment inquiry 21 years earlier, gave an unusual argument on behalf of Republicans and against impeachment. He didn't defend the president's actions or Trump himself. Turley noted he doesn't support Trump politically and even voted against him in the 2016 election. He did say he's a longtime friend of Trump's attorney general, William Barr.
But Turley also argued that Democrats were setting a dangerous precedent that could one day be used to smear one of their own.
"I get it. You're mad," he told the panel in his opening statement. "The president's mad. My Republican friends are mad. My Democratic friends are mad. My wife is mad. My kids are mad. Even my dog seems mad."
Impeachment though won't lessen that anger, he warned. Turley said he didn't think Trump's actions were a "clear case of bribery" and that Democrats should wait for the courts to weigh in on their demands for more documents and witness testimony.
Democrats have said they can't wait because Trump's actions present a "crisis" that must be addressed.
"That's why this is wrong," Turley said of impeachment. "It's not wrong because Trump is right. … It's wrong because this is not how you impeach an American president."
He urged Democrats to consider what they will do "when the wind blows again perhaps for a Democratic president."
"Where will you stand then?" he asked.
A conservative congressman attacked the panel as elitists
In perhaps the most explosive exchange of the day, Florida Republican Rep. Matt Gaetz attacked the panelists summoned by Democrats as politically motivated elitists and noted their past contributions to progressive campaigns.
According to records by the Federal Election Commission, Karlan has donated money to Sen. Elizabeth Warren's current presidential campaign, and Gerhardt donated money to both of President Barack Obama's election campaigns. Karlan also testified to having supported Hillary Clinton's campaign.
Gaetz, the conservative firebrand and provocateur who at one point crashed closed-door impeachment testimony, accused Karlan of living in "the ivory towers of your law school." He also criticized Karlan for making a joke about the president's teen son, Barron Trump.
Earlier in the hearing, Karlan was explaining that the Constitution was written in a way to make the U.S. president behave differently than a king, specifically excluding titles of nobility.
"While the president can name his son 'Barron,' he can't make him a baron," she said.
When it was Gaetz's turn to question the witnesses, he jumped on the remark as an attack on a "minor child."
"That does not lend credibility to your argument," Gaetz said. "It makes you look mean. It makes you look like you are attacking someone's family."
Karlan said she did not have contempt for conservatives and added, "I have a constitutional right to give money to candidates."
She later asked to apologize for alluding to Barron Trump.
"If I can say one thing, I want to apologize for what I said earlier about the president's son. It was wrong of me to do that," Karlan said. "I wish the president would apologize for the things he's said wrong, but I do regret having said that."
Republicans tried to throw sand in the gears early on
Republicans immediately tried to throw a wrench in the works with demands of procedural inquiries and roll call votes to force testimony from other witnesses.
The theatrics on Wednesday succeeded in slowing down the pace of the hearing and hammered away at a key GOP talking point: The impeachment process is unfair, the Republicans have said repeatedly.
Rep. Doug Collins of Georgia, the top Republican on the panel, opened the hearing by saying the Democratic quest for impeachment didn't start with Russia or election meddling but rather when liberal voters refused to accept the 2016 election results.
"This is not an impeachment. This is simply a railroad job and today's is a waste of time," Collins said.
Roles were reversed during Clinton's impeachment
A poster standing in the hearing room quoted longtime Rep. Jerry Nadler, now the House Judiciary Committee chairman, in 1998 making the same argument Republicans are pressing now -- that impeachment is unfair because it attempts to undo the results of a national election.
Nadler indeed railed against GOP impeachment efforts at the time, when Clinton was impeached for lying under oath to try to hide an extra-marital affair with White House intern Monica Lewinsky.
"There must never be a narrowly voted impeachment or an impeachment substantially supported by one of our major political parties and largely opposed by the other," Nadler said at the time of Clinton's impeachment. "Such an impeachment would lack legitimacy, would produce divisiveness and bitterness in our politics for years to come. And will call into question the very legitimacy of our political institutions."
On Wednesday, Nadler said one big difference between the two presidents is that Trump has refused to cooperate, noting Clinton's willingness to provide a blood sample to be tested for DNA at one point.
"President Trump, by contrast, has refused to produce a single document, and directed every witness not to testify. Those are the facts before us," he said.
Turley, the Republican-picked witness who also testified in 1998, noted that both impeachment proceedings were driven by hyper partisanship.
"The stifling intolerance for opposing views is the same," Turley said.
ABC News' Justin Fishel, Mary Bruce, Mike Levine and Benjamin Siegel contributed to this report.