National security expert explains why Americans should be terrified by ex-intel chiefs' warnings about Trump

A reporter who specializes in national security issues said former intelligence officials such as John Brennan would not be warning Americans about President Donald Trump if they did not believe he posed a grave threat.

Garrett Graff, former editor of Politico and now executive director of the Aspen Institute’s Cybersecurity & Technology Program, explained just how extraordinary those warnings were -- and he urged Americans to pay attention.

"Lost amid the controversy last week about Trump yanking Brennan's security clearance is just how unusual it is for any of these officials to be speaking publicly—and that fact alone should be cause for concern," Graff said.

These dire warnings about Trump's alleged ties to Russia and his efforts to undermine the rule of law to stop an investigation rise far above partisan sniping, Graff tweeted.

"This is no ordinary political criticism," he said. "Do not fall into Trump's trap that this is just more of the same, more partisan sniping from the Swamp from swamp creatures."

More than 60 former intelligence officials signed on to a letter denouncing Trump's attacks on Brennan and other critics, and Graff said their motives appeared to be consistent with their past work.

"These officials are not—repeat not—monetizing their security clearances by being on cable TV," Graff tweeted. "In fact, having covered many of these officials for years, I can tell you that they would prefer to be doing anything but being on TV."

He said those former officials were "speaking truth to power" to issue their warnings, after spending their careers avoiding politics, and he said that should give Americans a reason to trust them.

"These are not partisan hacks," Graff said. "They don't scare easily. They don't cry wolf."

"All of them were trained to keep quiet on politics," he added. "So the fact that they're not silent, that all of them — all of them — are screaming from the rooftops about Trump's threats to our country, our rule of law, our democratic institutions, should chill us."

"They are telling us this is a dark and dangerous time," Graff tweeted. "And they have spent their lives, devoted their entire careers, to protecting the country from just these sorts of events overseas. That they're warning us we're under threat at *home*. That's a warning worth listening to."