WATCH: Morning Joe’s Mika demolishes ‘pathetic and weak’ Paul Ryan for endorsing Trump

Morning Joe's Mika Brzezinski launched into a scathing attack Friday morning on Republican House Speaker Paul Ryan for caving and endorsing presumptive GOP presidential nominee Donald Trump this week.

After guest panelist Mark Halperin attempted to defend Ryan, saying "he had no choice," Brzezinski launched into a rant over the unsuitability of Trump as a representative of the Republican party.

"To your line about Ryan had no choice, which is pathetic, because this election is unlike any other, the rule book has been thrown out," she began. "So that no choice thing? Put it back into the 80's and 90's and early 2000's, because there are new rules."

Saying Ryan needs to "live by his principles," Brzezinski went on the attack addressing Ryan directly.

"Paul? He's not going to do anything for you because you did this," she exclaimed. "He's not going to pay you back. It's pathetic, he sold out. I'm sorry, he did have a choice and he made one that was weak."

Watch the video below via MSNBC below: