Alan Dershowitz, the Harvard Law emeritus professor who recently joined President Trump’s legal team, distanced himself Sunday from a response by two White House lawyers to House Democrats’ impeachment case against the president, noting that he did not sign onto the document.

“I didn’t sign that brief,” Dershowitz said in an interview on ABC News’s “This Week.” “I didn’t even see the brief until after it was filed. That’s not part of my mandate. My mandate is to determine what is a constitutionally authorized criteria for impeachment.”

Dershowitz is one of four lawyers who were selected personally by Trump and announced Friday as new members of the president’s legal team. The others are former Florida attorney general Pam Bondi and former independent counsels Robert Ray and Kenneth W. Starr.

Dershowitz’s comments come as both sides preview their arguments for Trump’s impeachment trial, which begins in earnest this week and is only the third such trial in U.S. history.

On Monday, the White House is expected to file a legal brief outlining why Trump should be acquitted.

House Intelligence Committee Chairman Adam B. Schiff (D-Calif.), the lead impeachment manager, said Sunday that Democrats will be “fighting for a fair trial” and pushed back against critics who have argued that the House should have done more to enforce its subpoenas before voting to impeach Trump.

“The reality is, because what the president is threatening to do is cheat in the next election, you cannot wait months and years to be able to remove that threat from office,” Schiff said on “This Week.”

Asked about a Politico report on the topic, Schiff also claimed that the CIA and the National Security Agency are withholding documents related to Ukraine under pressure from the White House and that intelligence officials are reluctant to testify publicly on global security threats because of fear of angering Trump.

“The NSA, in particular, is withholding what are potentially relevant documents to our oversight responsibilities on Ukraine, but also withholding documents potentially relevant that the senators might want to see during the trial,” he said. “That is deeply concerning. And there are signs that the CIA may be on the same tragic course.”

Trump has urged the Senate to dismiss the charges against him. Sen. Lindsey O. Graham (R-S.C.), a key Trump ally, said Sunday that such a motion is “dead for practical purposes,” but he noted that the president is eager for the trial to end as quickly as possible — ideally before his State of the Union address to Congress on Feb. 4.

“His mood is to go to the State of the Union with this behind him and talk about what he wants to do for the rest of 2020 and what he wants to do for the next four years,” Graham said on “Fox News Sunday.” “He is very much comfortable with the idea this is going to turn out well for him. He believes politically this has helped him.”

While Senate Majority Leader Mitch McConnell (R-Ky.) has yet to release his proposal for how the trial will be conducted, some GOP senators have suggested in recent days that their party may aim to condense the proceedings into as short a time frame as possible.

On NBC News’s “Meet the Press,” Sen. David Perdue (R-Ga.) said Republicans will probably propose a format that includes 24 hours of presentation by the House impeachment managers over two days, followed by an equal amount of time for a presentation by Trump’s legal team. That would be followed by 16 hours of questioning from members of the Senate.

Senators would submit their questions to Chief Justice John G. Roberts Jr., who is presiding over the trial. The issue of witnesses would then be addressed, Perdue said.

Senate Minority Whip Richard J. Durbin (Ill.) said Sunday that he and other Senate Democrats still haven’t heard from McConnell regarding his proposed outline for the trial.

“There hasn’t been the most basic negotiation or exchange of information,” Durbin said on “Meet the Press.”

Democrats on Saturday released a 111-page legal brief laying out their case against Trump, arguing that the president withheld a White House meeting and congressionally appropriated aid to pressure Ukraine into announcing investigations into former vice president Joe Biden and his son Hunter.

Aides to the House managers team said the managers and staff met Sunday to continuing discussing the trial strategy and to refine drafts of arguments that have been written over the previous weeks.

One Democratic aide said that all seven managers would present the case against Trump to senators “repeatedly” during the trial. House Speaker Nancy Pelosi (D-Calif.) chose a racially and geographically diverse team of seven managers, all with legal or law enforcement backgrounds, led by Schiff.

“They’ll each have their own role,” said the aide, who was not authorized to comment publicly and spoke on the condition of anonymity. “You’ll hear them explain the overwhelming, devastating evidence that the president of the United States pressured a foreign government interfere in a U.S. election to cheat on the upcoming election. But they’ll bring their own life experiences to bear.”

White House lawyers Jay Sekulow and Pat Cipollone penned a seven-page response in which they said there was no basis for either of the two articles of impeachment facing the president: obstruction of Congress and abuse of power.

Since joining the White House team, Dershowitz has made headlines for some of his unorthodox remarks about Trump’s impeachment.

In a BBC interview on Saturday, Dershowitz said he does not plan to vote for Trump in November and declared that if the Senate votes to acquit the president, it would create “ambivalence in me as it does whenever I represent somebody whose acquittal would produce results that make me unhappy as an individual.”

He added: “But I would never, ever allow my own partisan views to impact my views on the Constitution.”

On Sunday, Dershowitz argued that even if all of the facts presented by Democrats are true, Trump’s actions still do not constitute impeachable offenses — regardless of whether one believes Trump’s dealings with Ukraine were “wrong.”

“If the allegations are not impeachable, then this trial should result in an acquittal, regardless of whether the conduct is regarded as okay by you or by me or by voters,” he said on “This Week.” “That’s an issue for the voters.”

Democrats countered by calling Dershowitz’s defense “nonsense.”

“There is ample evidence, overwhelming evidence,” House Judiciary Committee Chairman Jerrold Nadler (D-N.Y.), who is also an impeachment manager, said on CBS News’s “Face the Nation.” “Any jury would convict in three minutes flat that the president betrayed his country by breaking the law.”

Dershowitz has also drawn scrutiny for the choice of clients he has previously represented.

In the mid-2000s, Dershowitz and Starr were part of Jeffrey Epstein’s legal team when the wealthy investor was under investigation on suspicion of child prostitution. Epstein, a convicted sex offender, was found dead in his jail cell last year in an apparent suicide.

Dershowitz also advised the defense team in former football star O.J. Simpson’s murder trial.

On CNN’s “State of the Union,” host Brianna Keilar pressed Dershowitz on his previous defense of clients some might find “unpalatable.” Dershowitz responded that he was proud of his record of defending “some of the most controversial people in American history.”

Senators and their constituents “understand that it’s pure McCarthyism to hold a lawyer responsible for having represented controversial clients,” Dershowitz said.

Interviewers on the Sunday-morning news shows pressed Democrats on one predicament they may quickly face during the Senate trial: Should they bow to Republican demands for “reciprocity” by agreeing to call witnesses the GOP desires — such as Hunter Biden, who accepted a lucrative board post with a Ukrainian energy company — in addition to those Democrats are seeking?

On “Face the Nation,” Nadler would not directly answer a question on the topic, saying only: “Any Republican senator who says there should be no witnesses — or even that witnesses should be negotiated — is part of the coverup.”

Sen. John Cornyn (R-Tex.) also questioned the credibility of businessman Lev Parnas, who earlier this month provided the House with documents detailing his apparent effort in concert with Trump attorney Rudolph W. Giuliani to orchestrate the ouster of Ambassador Marie Yovanovitch, the U.S. envoy to Kyiv who was fired last year under pressure from Trump allies.

Cornyn dismissed Parnas as someone “who’s trying to get leniency from the prosecutor and who has ties to Russian oligarchs.”

“Russians had a lot to do with our elections and disinformation campaigns, and this could be part of it,” he said on “Face the Nation.”

Nadler said Parnas is credible to the point that his claims have been backed by documents he has provided and other materials.

“Everything he says corroborates things we knew,” he said.