Giuliani agreed with the letter's finding that Trump has unlimited power to pardon while saying, in a separate appearance on NBC's "Meet the Press," that pardoning himself would probably lead to impeachment.
Norm Eisen, the White House ethics lawyer under President Barack Obama and now a senior fellow at the Brookings Institution, said the silliness of Giuliani's claim illustrates how mistaken Trump's lawyers are about presidential power. Finally, the letter says, although Trump may have helped Donald Trump, Jr. lie about the meeting at Trump Tower in which a purported Russian government official was supposed to provide dirt on Hillary Clinton, that was just "a private matter with the New York Times", not an interview with the Federal Bureau of Investigation, and therefore not a crime about which he can be questioned. "In this investigation, the crimes are really silly", he said, arguing that the firing of Comey previous year could not be construed as obstruction of justice because Trump had the right to fire him at any time and for any reason. He was answering a question related to Robert Mueller's "Russiagate" probe. "Pardoning other people is one thing, pardoning yourself would be tough". The White House denies that Trump said what Comey alleges.
Giuliani also defended the legal letter's broad claims about the president's power over the investigation itself Sunday, describing the U.S. Department of Justice as a "creature of the president". "If he's making an implicit threat that he could escalate this with pardons, there's nothing in the letter to indicate that he's not willing to pardon himself". But, Giuliani added: " I'm a lawyer ...
Giuliani added that it is a "a really interesting constitutional argument".
Mr Giuliani told ABC it was an "open question" whether Mr Trump would sit for an interview with Mr Mueller, but the President's lawyers were leaning against having him testify.
He has requested an interview with the president over obstruction of justice.
Trump lawyer Rudy Giuliani, last seen celebrating his birthday by being booed at Yankee Stadium, appeared on ABC's "This Week" with George Stephanopolous Sunday morning.
The letter is dated January 29 and addressed to Mueller from John Dowd, a Trump lawyer who has since resigned from the legal team.
The talk of self-pardoning has raised eyebrows amid the roiling debate over the Russian Federation meddling inquiry and the president's cooperation - or lack of it. As arguments against even asking him about the statements, they strike me as pretty silly.
Trump has consistently rubbished the investigation into potential collusion between his campaign and Russian Federation, labelling the probe "fake news" and a "hoax".