"A lot of people have been saying, 'Look, Donald has some problems,' and I think he realizes that he's got to make some changes going forward," Ruddy said in an interview with The Washington Post.
Ruddy went on to detail his critique of White House Chief of Staff Reince Priebus: "It's my view that Reince is the problem. I think on paper Reince looked good as the chief of staff — and Donald trusted him — but it's pretty clear the guy is in way over his head. He's not knowledgeable of how federal agencies work, how the communications operations work. He botched this whole immigration rollout. This should've been a win for Donald, not two or three weeks of negative publicity."
Ruddy insisted that he was speaking only for himself and not for the president, and he would not reveal whether Trump had confided in him about Priebus, saying the conversation was private.
White House spokesmen did not respond to a request for comment on Ruddy's statement.
Early Sunday evening, Ruddy attempted to soften his criticism of the White House chief of staff, saying in a tweet that he had just spoken with Priebus.
"Reince just briefed me on new WH plans. Impressive!" he tweeted. "Told him I have 'open mind' based on his results."
Ruddy — who is chief executive of Newsmax Media and a member of Trump's Mar-a-Lago Club in Palm Beach, Fla. — spoke to The Post shortly after appearing on CNN, where he threw Priebus under the proverbial bus.
"I think there's a lot of weakness coming out of the chief of staff," Ruddy told anchor Brian Stelter in a live interview from Miami. "I think Reince Priebus [is a] good guy, well-intentioned, but he clearly doesn't know how the federal agencies work. He doesn't have a really good system. He doesn't know how the communications flow."
Trump, Ruddy continued, is "not getting the backup he needs" from Priebus.
Ruddy said he spent about 30 minutes talking privately with Trump late Friday at Mar-a-Lago after the president's dinner with Japanese Prime Minister Shinzo Abe, after Abe had retreated to his suite for the night.
"Since the [CNN] show, I've gotten three text messages from sitting Cabinet members praising my appearance," Ruddy said. "They realize this whole government depends on this chief of staff."
He declined to identify the Cabinet secretaries.
Ruddy praised White House press secretary Sean Spicer and other administration officials who have come under public scrutiny. He said blame for missteps at the dawn of Trump's presidency should fall squarely on Priebus.
"What I'm hearing from a lot of people on the inside is that Reince is not giving Donald the pushback that he needs," Ruddy said. "He just doesn't have the gravitas that Donald would respect at the end of the day."