On the road promoting his new book, “A Higher Loyalty,” former FBI Director James Comey made a stop on “The Late Show with Stephen Colbert.”

While Comey’s anticipated interview with George Stephanopoulos last Sunday evening only managed an “okay” ratings grab (a bit over 9 million), the book is generating plenty of heat, with both Amazon and the New York Times placing it at the top of their best sellers lists.

In Tuesday night’s appearance, the former G-man was kicked back and casual, giving quite a few surprising nuggets to the questions being asked by Colbert.

For one thing, he didn’t think he’d be fired (even after refusing Trump’s barely-veiled request for loyalty).

Explaining his shock over being fired:

“I actually was quite surprised because I thought, ‘I’m leading the Russia investigation,’ ” Comey said, laughing. “Even though our relationship was becoming strained, there was no way I was going to get fired or whacked.”

“Why, why wouldn’t you get fired?” Colbert asked.

“Because that would be a crazy thing to do,” Comey responded. “Why would you fire the FBI director who’s leading the Russia investigation.”

“Because you’re leading the Russia investigation!” Colbert shot back, laughing. “I don’t know if you’ve dealt with mob bosses before, but they don’t like being investigated.”

Colbert’s last comment could be related to a previous musing of Comey, who said dealing with the Trump White House was like dealing with the mob. There was the secrecy, the reaction of Trump to being corrected, and the immediate circling around him by a close-knit cabal of advisers, shielding him against anything that might resemble commonsense or rational thought.

Also in his appearance with Colbert, Comey suggested that everything the public thinks they know about the beginnings of the Russia probe, aren’t necessarily all the things.

“Are there things that you know about the Russia investigation that were happening before you were fired that we haven’t learned yet as a public?” Colbert asked the former FBI chief.

“Yes,” Comey responded.

“Can you tell me what those are?” Colbert continued, to laughs.

“No,” Comey answered, chuckling. “No, and they’re not in the book. I had to have my book reviewed by the FBI to make sure it didn’t contain classified information or sensitive investigative information, so it’s not in the book.”

“OK,” Colbert responded, motioning to a cup of red wine near Comey. “Drink some more wine.”

Some have suggested that the former director may be in hot water with the book, but if it was already reviewed and given a clean bill by the FBI, that’s probably not the case.

So much for the fever dreams of the Trump faithful.

President Trump, of course, couldn’t help but tweet-rage about the Comey interview.

Slippery James Comey, the worst FBI Director in history, was not fired because of the phony Russia investigation where, by the way, there was NO COLLUSION (except by the Dems)!

— Donald J. Trump (@realDonaldTrump) April 18, 2018

For starters, I’m not of the belief that Donald Trump is schooled enough on the history or workings of the FBI to make a determination on who the “worst” FBI director may have been.

Second of all, Trump literally said to the world that, even before the recommendations he asked for from Attorney General Jeff Sessions and Deputy Attorney General Rod Rosenstein, he’d planned to fire Comey because of (to use his words) the “Russia thing.”

Shortly after, Trump took Russian officials behind closed doors, shutting out the press, and told them that firing Comey took pressure off of him.

Yeah. That’s also the meeting where he betrayed U.S. allies (Israel) and revealed sensitive information on an Israeli spy embedded with ISIS in Syria, and intel on explosives in laptops.

Trump had every right, as president, to fire Comey – no reason necessary, beyond wanting his own pick in that office – but he took legitimate statements from his people, trashed them, then cast doubt on himself with his own words.

That’s not Comey’s fault. It’s not Jeff Sessions’ fault (Sessions gave him cover, and he immediately blew it), or even Rod Rosenstein’s fault.

Trump’s inability to play the role of a reasonably sane, normal individual is what has him in hot water today.

He can’t go back today and pretend he never said what he said.

You can watch Comey’s interview here: