Donald Trump called out MSNBC host Joe Scarborough on Twitter. | Getty Trump rips Joe Scarborough

Now that he is the presumptive Republican nominee, Donald Trump has begun calling out those who were not always 100 percent in his corner.

"Joe Scarborough initially endorsed Jeb Bush and Jeb crashed, then John Kasich and that didn't work," Trump tweeted Friday afternoon. "Not much power or insight!"


Scarborough retweeted the message.

Less than 30 minutes later, Trump wrote, "I hear @JoeNBC of rapidly fading @Morning_Joe is pushing hard for a third party candidate to run. This will guarantee a Crooked Hillary win."

This time, Scarborough engaged:

You heard wrong, cowboy. We talk about scenarios. Never fear. MJ is going to beat CNN for the 7th straight year! �� https://t.co/DVsBHctzgd — Joe Scarborough (@JoeNBC) May 6, 2016

"Rapidly fading?" Umm...we are enjoying our best ratings ever. Lots of luck, fella. https://t.co/DVsBHctzgd — Joe Scarborough (@JoeNBC) May 6, 2016

I also said very clearly that good conservatives have legitimate reasons for being in the #NeverTrump column. https://t.co/hRQpcTccgw — Joe Scarborough (@JoeNBC) May 6, 2016

Your ears are deceiving you. I've repeatedly said conservatives have many honorable reasons for opposing Trump. https://t.co/Gk744GOwcl — Joe Scarborough (@JoeNBC) May 6, 2016

Throughout the primary race, Scarborough and co-host Mika Brzezinski have forcefully struck down assertions that their show has beaten the drum in favor of Trump, taking pains to emphasize after lengthy (usually phoned-in) interviews with the candidate that every candidate has a standing invitation to the show.

Scarborough, who served in the House from 1995 to 2001, has also flirted with the idea of being Trump's running mate, though he has denied that he would seriously consider it.