President Donald Trump on Thursday granted Attorney General William Barr the authority to declassify information relevant to the investigation into how spying on the Trump campaign started in 2016. Former CIA Director John Brennan appeared on MSNBC's "All in with Chris Hayes" to discuss the decision.

According to Brennan, Barr investigating the origins of the Russia probe is "outrageous."

"How big a deal do you read the portion of the executive order last night that appears to give [Attorney General William] Barr the unilateral authority to declassify?" Hayes asked.

"Well, I see it as a very, very serious and outrageous move on the part of Mr. Trump, once again, trampling on the statutory authorities of the Director of National Intelligence and the heads of the independent intelligence agencies. And it's unclear to me what Mr. Barr is actually going to do. Is he investigating a crime? Well, what's the predication of that crime? Or is he just going to be looking for information?" Brennan asked.

"I think it's rightly, as you pointed out, right at the top, that Mr. Trump can just give to just some of his defenders on the right and cherrypick information that could be taken out of context. But, I think more fundamentally, is the concern is that very, very precious source and methods of the United States intelligence community, as well as our partners and allies abroad, those who share this sensitive information with us," Brennan explained. "Is Mr. Barr, who doesn't have an understanding of the equities involved, is he just going to release information he deems appropriate for Mr. Trump's defense? So this is very serious and I know my former colleagues in the intelligence agencies are looking upon this with great concern and worry."

When will Democrats and the mainstream media give it up? They wanted Trump investigated. They got their investigation. They got to pick their guy – Special Counsel Robert Mueller – and he found no collusion and no obstruction. In fact, it was revealed that the FISA warrants that were used to start the probe weren't vetted. The American people want to know how so much of their taxpayer funds were used for this phony investigation. They want to know exactly how this started so it never happens again.

Democrats hate Barr because he's not giving into their political whims. They wanted him to release Mueller's full report but he didn't because he followed the rule of law. Grand jury testimony is not allowed to be made public.

Democrats hate Barr because he doesn't sit back and take their crap. He's willing to use his intelligence to fight fire with fire.

Democrats hate Barr because he's going to expose their shenanigans and how this witch hunt began.

Buckle your seats, folks. This is about to be a bumpy ride.