Former President turned author Bill Clinton said Sunday that former President Barack Obama received friendlier treatment in the press than other Democrats and Republicans, in part because the media liked having an African-American in the office.

Clinton is out promoting his new novel, The President Is Missing, a potboiler about a chief executive who goes rogue to fight terrorists. It was cowritten with best-selling author James Patterson.

Speaking on CBS This Morning, Clinton talked about why the political press gave friendly coverage to Obama.

At first he said, “Why? ‘I don’t know,'” then added, “They liked him. And they liked having the first African-American president, and he was a good president I think,” Clinton said. “I don’t agree with President Trump’s assessment of his service.”

Clinton addressed several topics, including that he knew the attempt to impeach him would not succeed. A majority of House of Representative members must vote for charges in order to impeach the president. After the charges of misconduct are filed, the Senate has the power to try impeachment cases like a court. Two-thirds of the senators must vote for conviction.

Clinton was charged with perjury and obstruction of justice for lying about his relationship with then-White House intern Monica Lewinsky. He was acquitted by the Senate.

“Well, I knew it wouldn’t succeed,” Clinton said. “It wasn’t a pleasant experience. But it was a fight that I was glad to undertake after the elections, when the people had solidly told, by two-thirds or more, the Republicans to stop it. They knew there was nothing impeachable. And so, we fought it to the end. And I’m glad.”

As for his literary skills, Clinton claimed they stem from being an avid reader. “I’ve consumed literally thousands and thousands of thrillers, political novels, all this kind of stuff.”  As for Patterson, “He’s just good at it. But I wanted it to be real,” Clinton said. “I didn’t want anybody to be able to say, ‘Oh, this is just made up bull,’ you know?”

“The worst possible attack on the United States happens in this book. And if it happened, this is the way it would happen,” Patterson said. “There’s a traitor in the White House. If it happened, this is authentically how it would happen.”