Newt Gingrich on Friday blasted Donald TrumpDonald John TrumpKey takeaways from the Arizona Senate debate Major Hollywood talent firm considering rejecting Saudi investment money: report Mattis says he thought 'nothing at all' about Trump saying he may leave administration MORE for his late-night tweeting, saying there is "no excuse" for such behavior.

ADVERTISEMENT

"What Trump has got to understand, he's got to sing either, 'I got to be me' or he's got to order a new song, 'I've got to be President.' They're not the same song. He's got to become much more disciplined," Gingrich said in an interview with Fox News' Sean Hannity.

"For a while there, I thought he had really turned a corner. This last week, I think has been, frankly, a lost week. A week which has hurt him. Which has shaken his own supporters."

"You can't tweet at 3 o'clock in the morning. Period. There's no excuse. Ever. Not if you're going to be president of the United States," he added.

Trump went on a Twitter rant early Friday morning attacking Hillary ClintonHillary Diane Rodham ClintonCarter Page files defamation lawsuit against DNC Dems fear party is headed to gutter from Avenatti’s sledgehammer approach Election Countdown: Cruz, O'Rourke fight at pivotal point | Ryan hitting the trail for vulnerable Republicans | Poll shows Biden leading Dem 2020 field | Arizona Senate debate tonight MORE and questioning the reputation of the former "Miss Universe" Alicia Machado.

He accused the Democratic nominee of using Machado as a debate tool and urged his followers to "check out sex tape and past" of the former model. There is no proof Machado was involved in any sex tape.

Trump later defended his rant, tweeting that "at least you know I will be there, awake, to answer the call!"
Gingrich advised Trump to stay on the issues and avoid "getting down in the mud" in the future.

"I really hope this is a wakeup call for him. Quit tweeting without somebody looking over your shoulder, don't ever tweet late at night and prepare to really study and get ready for a serious debate because ... this next debate is going to be very important for how people judge him," he continued.
 
Trump and Clinton are set to face-off in the second presidential debate on Oct. 9.