Toward the end of my third campaign interview with Donald Trump, I finally got a glimpse into why he spends so much time and energy attacking journalists.

Not that there’s anything wrong with that. I told the Republican front-runner in our Trump Tower sitdown on Friday that he has every right to hit back at media people who criticize him, and there’s been no shortage of harsh criticism.

What I wanted to know is why he’s so obsessive about it. Why he’s calling out lesser-known reporters at rallies. Why he’s using Twitter to slam cable news commentators and guests around the clock. Whether calling them dopes and losers is presidential.

As we sparred over Trump’s view of the political press as dishonest, he said:

“It’s good when I fight them. First of all, it makes me feel good. Second of all, second of all, it takes away credibility. You have to fight for yourself. That’s the problem with our country, we don’t fight for ourselves.”

Ding ding ding ding. Now it’s becoming clear.

Since I had asked whether he can’t restrain himself, Trump was refreshingly candid: He whacks them because it makes him feel good. So there.

Trump also thinks it damages their credibility when he takes them on. Since the commentators are ripping him, and some journalists are reporting things in a way he finds unfair, it helps him to take them down a notch or two.

But it’s the last part of his answer that gets at the essence of his candidacy. Trump casts his battle as fighting for himself—and then quickly pivots to saying we don’t fight for ourselves in this country.

So his constant warfare with the pundits can serve as a proxy for how he wants to be seen: as a take-no-prisoners guy who would be as tough on America’s enemies as on the widely distrusted media.

The impassioned reaction to this “Media Buzz” interview tells much about the divide in the country.

Trump fans tended to like the interview, but some complained about the liberal media trashing Trump and other conservatives. And yet, as I told him on camera, it’s commentators on the right, including some at Fox, who have been among his harshest critics because they don’t believe he’s a true conservative.

Trump haters complained about television in general and me in particular giving him so much air time, claiming that if not for us he wouldn’t be riding high in the polls.

That critique gives the media way too much credit and Trump too little credit for connecting with as much as 40 percent of Republican primary voters who are disaffected, don’t trust the establishment, admire the business he built and think he’ll be tougher on terrorism than his rivals.

It also ignores Trump’s skill in working the news cycle and seizing control of the campaign dialogue, sometimes with comments that are over the top, or that people find offensive.

The bottom line is that this guy makes himself more available for journalistic questioning than any candidate since I was riding on John McCain’s bus in 1999 and 2000. The other candidates could do that, but are much more selective in their media appearances. I’ve had seven other presidential candidates on the show this year, but sometimes it takes months of repeated requests to book them.

Trump simultaneously works the media and works over the media, which is a bit of a feat if you can pull it off. And now we know a bit more about why he does it.

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.