Adam Schiff, lead impeachment manager in the Senate trial of Donald Trump, has called arguments made by the president’s defence team a “descent into constitutional madness”.

Mr Schiff’s indignation with the president’s defence came in response to comments made by Mr Trump’s lawyer, Alan Dershowitz, who argued his client couldn’t be impeached for an action he thought might get him re-elected.

“It’s astonishing on the floor of this body someone would make that argument. It didn’t begin that way in the beginning of the president’s defence. What we have seen over the last couple of days is a descent into constitutional madness because that way madness lies,” Mr Schiff said.

Mr Dershowitz made his argument on Wednesday in response to a question from Senator Ted Cruz asking if there was any significance to Trump engaging in a “quid pro quo”.

“Every public official that I know believes that his election is in the public interest,” Mr Dershowitz said. “And if a president does something which he believes will help him get elected in the public interest, that cannot be the kind of quid pro quo that results in impeachment.”

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Mr ​Dershowitz did make exceptions for quid pro quo agreements that included illegal acts or those made solely for personal gain.

Mr Schiff said that only someone who knew their client was guilty would make that argument.

“The only reason you make that argument is because you know that your client is guilty and dead to rights. That is an argument made of desperation,” Mr Schiff said.

Mr Dershowitz isn’t just taking flak from his opponents in the Senate.

While arguing that the constitutional framers did not believe “abuse of power” to be a removable offence for an impeached president, Mr Dershowitz frequently cited Harvard law professor Nikolas Bowie, who took to Anderson Cooper’s show on CNN to roundly disagree with Mr Dershowitz.

“Abuse of power is a crime, there are people around the country who have been convicted of it recently, they’ve been convicted of it since this country was founded. It’s a criminal offence,” Mr Bowie said. “To equate it with maladministration, as my colleague Professor Dershowitz does, is the equivalent of saying criminal corruption is the same thing as getting a bad performance evaluation.”

Mr Dershowitz attempted to clarify his statements on Thursday afternoon in a series of tweets, claiming that media outlets “willfully distorted” the answers he had given.

“They characterised my argument as if I had said that if a president believes that his re-election was in the national interest, he can do anything,” Mr Dershowitz tweeted. “I said nothing like that, as anyone who actually heard what I said can attest.”

Despite Mr Dershowitz’s protest that he was misunderstood, Senate Minority Leader Chuck Schumer said he wasn’t buying the self-correction.

“He gives a statement on the floor and then spends the next day correcting it. What a load of nonsense,” the leading Democrat said during a press conference.

Possibly most damning was the response to Mr Dershowitz that came at the hands of Senator Jerry Nadler, who played a video of Mr Dershowitz from 1998 – during the impeachment of president Bill Clinton – in which he argues that “there need not be a technical crime” to impeach a president.

“It certainly doesn’t have to be a crime. If you have somebody who completely corrupts the office of the president and who abuses trust and poses great danger to our liberty, you don’t need a technical crime,” Mr Dershowitz said in the video.

Trump attorney Alan Dershowitz uses Middle East Peace Plan to explain quid pro quos during impeachment hearing

Despite the flood of criticism for his arguments, the lawyer – whose previous clients have included Jeffrey Epstein and OJ Simpson – maintained well into Thursday that he was being smeared based on a misunderstanding.