New York magazine has a good profile of Joe Scarborough and Mika Brzezinski:
Sources close to Trump told me he’s angered by what he perceives to be the phoniness of Scarborough and Brzezinski, the very sort of Washington bullshit he campaigned against in the first place: To his face, and to other members of his administration, they’re friendly; to the cameras, it’s a different story. And those sources in the White House believe the shift in tone on Morning Joe reflects a combination of frustration at being shut out of Trump’s orbit and simple jealousy — Scarborough has always been thought to have presidential aspirations. “He wanted to be president, and he’s not. And, of all people, Donald Trump is. This is crazy,” a second senior White House official said. “They lost access in month two, month one, of a White House where part of their stock-in-trade was ‘Donald this’ and ‘Donald that’ and ‘The president told me this’ and ‘People close to the president told me that.’ It became very obvious around here who they talked to every day, and it wasn’t the president.”
Scarborough and Brzezinski said the White House is misrepresenting their motivations, though they didn’t rule out that Scarborough might be interested in running for president in the future.