Former Director of National Intelligence James Clapper had strong words for President Donald Trump on Tuesday night, calling Trump's performance at a campaign rally in Arizona "downright scary and disturbing."

"It's hard to know where to start," Clapper told CNN anchor Don Lemon. "It's just so objectionable on so many levels."

"You know, I've toiled in one capacity or another for every president since, and including, John F. Kennedy through President Obama, and I don't know when I've listened and watched something like this from a president that I've found more disturbing," Clapper continued.

Trump held a campaign rally Tuesday evening amid a cheering crowd and discussed many topics, including the Charlottesville, Virginia, protests, North Korea, and the US-Mexico border wall.

"I find this downright scary and disturbing," Clapper said. "This is not a surprise. It's interesting to contrast last night's teleprompter Trump performance versus tonight, which is of course, the 'real' Trump, just as it was at the unglued impromptu press conference at Trump Tower."

Clapper also cast doubt on Trump's ability to lead: "I really question his ... fitness to be in this office. And I also am beginning to wonder about his motivation for it. Maybe he is looking for a way out."

"He should've quit while he was ahead last night," Clapper said, referring to Trump's measured speech Monday night about his strategy for the war in Afghanistan. "But again, I think the 'real' Trump came through."

But Clapper wasn't finished with his critical assessment of Trump: "This behavior and this divisiveness, and the complete intellectual, moral, and ethical void that the president of the United States exhibits — how much longer does the country have to, to borrow a phrase, 'endure this nightmare'?"

Watch the clip here: