‘What’s in the water in Trump country?’: MSNBC panel baffled by conservatives refusal to accept MAGABomber evidence
Supporter of President Donald Trump wearing a "Trump -- Make America Great Again" hat at a rally (Screengrab)

Some supporters of President Donald Trump have simply refused to accept the fact that Cesar Sayoc Jr. -- the MAGABomber -- was a Trump superfan who had attended at least one "Make America Great Again" and watched Fox News.

The topic was discussed on MSNBC's "Up with David Gura" on Saturday morning.

"Mara, let me ask you what's in the water in Trump country?" Gura asked Mara Gay, of The New York Times editorial board. "What was fringe is now brought into the mainstream, at least again in this part of Trump country."

"I think one of the most disturbing things about the time we're living in now, this idea that this assault on truth, and the assault on facts, and on factuality," she answered.

"Once you've got a certain segment of the population kind of believing that there is no fact -- there's no such thing as truth -- it's just about, you know, their belief in Donald Trump," she explained. "So they believe the messenger no matter what he says."

"It's a very scary place to be, and probably a long conversation to be had about how we got here.

"You know, I don't think that there are any facts we could show some people in this country at this point that would convince them of a narrative that they don't want to believe," she continued.

"The problem because of attacks on the media, undermining the media's credibility, people just don't believe anything the media says," noted former federal prosecutor Daniel Goldman.

"Of course, the media is the messenger of the information to the public, so if you don't believe the messenger because of these attacks about fake news and the attacks on the freedom of the press, then you're not going to believe any of the facts, because you just think they're made up," he continued.

"That is the most dangerous, perhaps, thing that Trump is doing in this era," the former prosecutor concluded.