Call it the revenge of the conservative nerds.

Commentators on the right, who fiercely opposed Donald Trump during the primaries, are now savaging him in harshly personal terms. They are having an I-told-you-so moment.

With Trump going through the roughest stretch of his campaign, many of these commentators seem to feel vindicated. We might have expected them to mute their criticism once Trump won the Republican nomination, or grudgingly argue that he is at least preferable to Hillary Clinton.

Instead, they are doubling and tripling down.

Here’s why it matters: At a time when liberal commentators are outright mocking Trump and the mainstream press is downgrading his chances, the erosion on the right has left him with few defenders. The columnists who might help defuse the political and journalistic bombs being hurled at him instead are firing their own ammunition.

Trump, of course, managed to win the GOP nomination over the opposition of the National Review and Weekly Standard crowd. His supporters dismissed the conservative elite as out-of-touch intellectuals who spent their time at conferences and cruises. And the candidate won nearly 14 million primary votes.

But just when he needs to expand his base, and is slipping in the polls, he’s taking heat from the right as well as the left.

Now Trump has some conservative defenders like Laura Ingraham, who spoke at the Cleveland convention, Sean Hannity, Hugh Hewitt and others. But some of those with mighty megaphones are far louder.

I offer these excerpts not because I agree with them, but to convey the tone of these assaults.

One who admittedly went over the top was Red State founder Erick Erickson, now blogging at The Resurgent. He slammed Trump’s supporters:

“Donald Trump wants to turn NATO into a damn shakedown scheme and you people are cheering him on. You should be ashamed of yourselves. You should be ashamed of the fact that your cult leader who claims to have been personally affected by 9/11 does not even know our NATO allies protected his [butt] that day...

“You people reflect the evil character of your god...You disgust me in cheering him on.” 

Erickson realized he had gone too far and apologized on Facebook.

David Brooks unloaded in the New York Times:

“With each passing week he displays the classic symptoms of medium-grade mania in more disturbing forms: inflated self-esteem, sleeplessness, impulsivity, aggression and a compulsion to offer advice on subjects he knows nothing about.

“His speech patterns are like something straight out of a psychiatric textbook.”

Wow.

“He also cannot be contained because he lacks the inner equipment that makes decent behavior possible. So many of our daily social interactions depend on a basic capacity for empathy. But Trump displays an absence of this quality…He is a slave to his own pride, compelled by a childlike impulse to lash out at anything that threatens his fragile identity.”

Charles Krauthammer, perhaps Trump’s most prominent critic on Fox, seemingly uses his training as a psychiatrist to diagnose the candidate:

“It’s that he can’t help himself. His governing rule in life is to strike back when attacked, disrespected or even slighted. To understand Trump, you have to grasp the General Theory: He judges every action, every pronouncement, every person by a single criterion — whether or not it/he is ‘nice’ to Trump.

 “This is beyond narcissism…His needs are more primitive, an infantile hunger for approval and praise, a craving that can never be satisfied. He lives in a cocoon of solipsism where the world outside himself has value — indeed exists — only insofar as it sustains and inflates him.”

Some of Krauthammer’s words on Fox are being used in a Hillary ad.

The Wall Street Journal's Peggy Noonan has jumped on the crazy train:

"Here is a truth of life. When you act as if you’re insane, people are liable to think you’re insane. That’s what happened this week. People started to become convinced he was nuts, a total flake."

George Will, who took the step of leaving the Republican Party, accuses Trump of practicing “post-factual politics”:

“He seems to understand that if you produce a steady stream of sufficiently stupefying statements, there will be no time to dwell on any one of them, and the net effect on the public will be numbness and ennui. So, for example, while the nation has been considering his interesting decision to try to expand his appeal by attacking Gold Star parents, little attention has been paid to this: Vladimir Putin’s occupation of Crimea has escaped Trump’s notice.

Will says politics is “being poisoned by the injection into its bloodstream of the cynicism required of those Republicans who persist in pretending that although Trump lies constantly and knows nothing, these blemishes do not disqualify him from being president.

And Bill Kristol, who led the search for a third-party alternative, even trying to recruit NR’s David French, says Trump’s Republican supporters, are in “a pathetic and contemptible place…All of these Republicans have expressed support for Trump. They're prominent people with access to Trump. They should persuade him in private to improve his campaign. Or they should give up and go on a long vacation. Or, if they have come to the belated realization that Donald Trump should not be the next president of the United States, they should stand up and say so.” And Kristol tells them to stop “whining to the press.”

Who needs liberals when your own side is indicting you this way?

The opposition is rooted in ideology, in that these pundits don’t believe that Trump is a real conservative. But it has mushroomed into something far deeper and more personal, a crusade to stop Trump at all costs.

None of these commentators is a fan of Hillary Clinton, but these attacks help her nonetheless.

Perhaps none of this matters. Trump is running against the media establishment in the same way that he ran against the political establishment.

But there is an animosity here that may have its roots in a sense of betrayal, the sense that the GOP betrayed them by nominating such a person. They sound even madder than the liberal pundits that Trump could win the White House.

Howard Kurtz is a Fox News analyst and the host of "MediaBuzz" (Sundays 11 a.m. and 5 p.m. ET). He is the author of five books and is based in Washington. Follow him at @HowardKurtz. Click here for more information on Howard Kurtz.