Rudy Giuliani realized he can't actually be Trump's impeachment lawyer because he's a witness in the case

Rudy Giuliani told ABC News that he would not be able to represent President Donald Trump during Trump's second impeachment trial because he was a witness in the case.

Giuliani appeared with Trump at the January 6 "Save America" rally where Trump is accused of inciting an insurrection — and where Giuliani called for "trial by combat."

It was widely expected that Giuliani, who served as lead counsel on the president's various challenges to the 2020 election, would head up Trump's impeachment legal team.

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Rudy Giuliani now says he won't be a part of President Donald Trump's impeachment defense team.

Calling himself a "witness," the president's personal attorney told ABC News' chief White House correspondent, Jonathan Karl, that he could not defend Trump against the charge of inciting an insurrection because he attended — and spoke at — the event at the center of the allegation.

Giuliani appeared at Trump's "Save America" rally on January 6 near the White House, where the lawyer told the crowd it was time for "trial by combat." The aggressive rhetoric at the rally is under scrutiny after many of the attendees marched straight to the Capitol in what became a riot that resulted in five deaths.

"If we are wrong, we will be made fools of," Giuliani said. "But if we're right, a lot of them will go to jail. So let's have trial by combat." (He later said he was simply making a reference to "Game of Thrones.")

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The New York State Bar Association has launched a formal investigation into whether Giuliani should be expelled over his comments at the rally.

Two sources close to the White House had previously told Reuters that Giuliani was on the shortlist to represent Trump during the president's second impeachment trial.

The former New York City mayor led the president's challenges to the certification of electoral votes in the 2020 election.

Giuliani is one of the few constants in the president's life, though last week The Washington Post reported that Trump had instructed his aides not to pay Giuliani's legal fees. The president was said to be outraged over Giuliani's reported $20,000-a-day fees and had stopped taking his calls.

The former Harvard Law professor Alan Dershowitz was also said to be among Trump's top picks for his impeachment defense team. He told The Boston Herald, however, that he would defend Trump in the "court of public opinion" but would not be a part of his legal team.