Newt Gingrich on Friday blasted Donald TrumpDonald John TrumpSanders apologizes to Biden for supporter's op-ed Jayapal: 'We will end up with another Trump' if the US doesn't elect progressive Democrats: McConnell impeachment trial rules a 'cover up,' 'national disgrace' MORE for his late-night tweeting, saying there is "no excuse" for such behavior.

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"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 ClintonDemocratic debates are magnet for lobbyists NYT editorial board endorses Warren, Klobuchar for Democratic nomination for president Sanders v. Warren is just for insiders 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. 
 
Gingrich, a close ally of Trump, was reportedly on the short list to be his running mate before the businessman eventually chose Indiana Gov. Mike PenceMichael (Mike) Richard PenceTrump, Pence visit MLK memorial JFK's grandson calls Pence op-ed a 'total perversion' of Kennedy's legacy Sunday shows preview: Lawmakers gear up for Senate impeachment trial MORE.