MSNBC's Joe Scarborough and Mika Brzezinski arrive for the annual White House Correspondents' Association dinner in D.C. on April 25, 2015. (Jonathan Ernst/Reuters)

Donald Trump's obsession with MSNBC's "Morning Joe" is so strong that he is starting to see things that aren't there.

Co-host Mika Brzezinski was certainly critical of Trump Friday morning, as she is most mornings, but there was nothing unusual about her commentary — certainly nothing that could be described even in hyperbolic terms as a "mental breakdown." It has long been clear that the Republican presidential candidate is thin-skinned, but he now appears so sensitive to scrutiny from a show once considered by some to be overly friendly toward him that he is inventing vicious attacks out of thin air.

Brzezinski and partner Joe Scarborough are currently living rent-free in Trump's head.

Trump has claimed several times that he doesn't watch "Morning Joe" anymore. Notice how Trump tweets about what he hears goes on during the show, giving the impression that he isn't actually tuning in. (Friday morning, he also tweeted several times about the strength of his ground game, and how much it would surprise the skeptics. Trump's ground game was covered in a segment of the show Friday morning featuring Fix founder Chris Cillizza.)

Sometimes, however, Trump slips.

Scarborough, for one, isn't buying Trump's act. The former Republican representative thinks Trump can't help but watch — and enjoys taunting him for it.

http://twitter.com/JoeNBC/status/767696649309347841

Whether he is watching or hearing, Trump always knows what Brzezinski and Scarborough are saying.

As the business mogul hurls insults, it is impossible not to notice that he takes a more strident tone toward the female half of the "Morning Joe" tandem. In the past two weeks alone, Trump has called Brzezinski "crazy," "very dumb," "insecure," "neurotic" and "not very bright." During the same stretch, he has referred to Scarborough as a "mess" and a "clown" — but also has applied those labels to Brzezinski. Trump has not taken a personal shot at Scarborough that he did not also take at Brzezinski, yet he has repeatedly questioned Brzezinski's intelligence and mental health.

Only one "Morning Joe" host has recorded a hyper-trolling song called "Amnesty Don." It was not Brzezinski.

It is this sort of imbalance that has contributed to charges that Trump is sexist. He disses men all the time, to be sure, but he only insulted the physical attractiveness of one primary opponent — "Look at that face!" he said of Carly Fiorina — and gender sure seemed to factor into his attacks on Megyn Kelly, such as when he retweeted a follower who called the Fox News host a "bimbo" and when he said there was "blood coming out of her wherever."

Trump has not paid a steep price for these episodes, however. Here he is, the GOP candidate, within striking distance of Hillary Clinton going into Labor Day weekend.

Will Trump's "Morning Joe" fury hurt him? The better question might be: Is he wasting his time?

Consider this passage from a New York Times story in February:

"Morning Joe" occupies a crucial place in the Washington-New York ecosystem. It is the default screen setting in the Senate gym, and considered must-watch television among the politerati. But it is unclear that the show wields as much influence outside the Beltway.

Trump is consumed by what Brzezinski and Scarborough say about him. But do swing-state voters care nearly as much?