Rove, a Fox News contributor, made the comments Friday during an appearance on the network to discuss a newly released document used to justify the FBI search of Trump’s home earlier this month. As Republicans have largely closed ranks in defense of Trump, Rove has emerged as an unexpected critic of the former president.

The U.S. Justice Department on Friday released a redacted affidavit stating Trump’s legal counsel had been advised in June that his private residence was not “authorized to store classified information” taken from the White House at the end of his presidency. The affidavit also stated that FBI agents found 184 classified documents recovered from Mar-a-Lago earlier this year.

Trump has denied wrongdoing, claiming he had the authority to declassify documents. But Rove, who served as top aide to former President George W. Bush, said presidents aren’t allowed to pick and choose which documents to take with them after leaving office.

“The Presidential Records Act is clear,” said Rove. “A president does not have the right to leave the White House and pick and choose what documents he wants to take with them. He can ask for copies, but those are the property of the American people.”

Rove said it was clear the National Archives and Records Administration had been asking for Trump to return the documents for a year and a half.

“Why he was holding on to these materials when he had no legal authority to do so under the Presidential Records Act is beyond me,” he said.

Previously, Trump had openly criticized Bush’s presidency, despite the two belonging to the same party. Bush has responded with veiled swipes at Trump, but Twitter users reacted with shock that Rove said a fellow Republican had violated federal law.

Katie Phang, host of MSNBC’s The Katie Phang Show, reacted with a tweet, “When Karl Rove is the voice of reason…”

“My god…,” actor Ken Olin said in a tweet. “If you’re a scummy Republican and Karl Rove says you’re guilty as fck, you’re guilty as fck.”

“I must be losing my mind because I think I’m listening to Karl Rove on @FoxNews rip on Trump and defend the FBI/DOJ,” Twitter user LiraLoudmouth said in a tweet.

“It’s happening…” tweeted comedian Heather Gardner. “Some of the Fox News regulars are finally starting to throw Trump overboard.”

Newsweek has reached out to Trump for comment.