Donald Trump Takes On Marco Rubio on Twitter

PHOTO: Presidential candidate Donald Trump during an interview on "The Tonight Show Starring Jimmy Fallon" on Jan. 11, 2016 | Senator Marco Rubio on "The Tonight Show Starring Jimmy Fallon" on Jan. 21, 2016 in Los Angeles.PlayGetty Images
WATCH Donald Trump Takes the Heat in GOP Debate

Sen. Marco Rubio has largely been spared from Donald Trump's Twitter attacks. That was until today.

After last night's Republican debate, where Rubio seemingly unloaded his oppo playbook on Trump, Trump decided he wasn't playing nice any longer.

He attacked the Florida senator on Twitter this morning, calling him a "lightweight," "Mr. Meltdown" and "a choker."

On "Good Morning America" and in other appearances Friday morning, Rubio said Trump was a "con artist."

On Tuesday, in Sparks, Nevada, Trump called Rubio "a nice young man" but warned, "I can’t hit him, he has not hit me, when he hits me -- Ugh he’s gonna be hit."