Rudy Giuliani, who this week said he would serve on Donald Trump’s impeachment defense team in a Senate trial, now says he can’t.

“Because I gave an earlier speech [at the January 6 Trump rally], I am a witness and therefore unable to participate in court or Senate chamber,” he told ABC News reporter Jonathan Karl.

Giuliani spoke at the rally inciting Trump supporters to storm the U.S. Capitol building, urging them to attack.

“If we are wrong, we will be made fools of,” Giuliani told the crowd. “But if we’re right, a lot of them will go to jail. So let’s have trial by combat.”

On FOX News Sunday, Republican strategist Karl Rove said a Senate defense led by Giuliani would cause GOP senators to jump ship and Trump would lose.

Said Rove: “Rudy Giuliani charted a very bad course for the president in the morning papers when he suggested that the argument was going to be, ‘Well, there couldn’t have been incitement because all the charges of widespread voter fraud are true.’ Well, those charges and the so-called experts that the campaign has mustered to advocate them have been rejected by over 50 courts, with judges appointed by President Trump, President Obama, President Bush, President Clinton, and I think even one Reagan justice. If it’s the Rudy Giuliani defense, there’s a strong likelihood that more than 17 Republicans will, because essentially that argument is: ‘This was justified, the attack on the Capitol and the attempt to end the congressional hearing on certifying the election was justified because all these charges are true.’ And frankly, they aren’t.”