GOP presidential front-runner Donald TrumpDonald John TrumpAmash responds to 'Send her back' chants at Trump rally: 'This is how history's worst episodes begin' McConnell: Trump 'on to something' with attacks on Dem congresswomen Trump blasts 'corrupt' Puerto Rico's leaders amid political crisis MORE promised late Thursday night that he would no longer curse on the campaign trail.

“I won’t use foul language,” he told supporters during a rally in Baton Rouge, La.

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“I’m just not going to do it. I’ll never do it again, actually, and I’ll never even copy what somebody asks me to say.”

Trump’s rivals for the Republican presidential nomination have criticized his public profanity as crass and undignified.

“I’m not sure a lot of voters are excited about having a president who, when he gets rattled or gets upset, he begins cursing and yelling vulgarities,” rival candidate Ted CruzRafael (Ted) Edward CruzCruz calls for 'every penny' of El Chapo's criminal enterprise to be used for Trump's wall after sentencing Conservatives defend Chris Pratt for wearing 'Don't Tread On Me' T-shirt Google official denies allegations of ties to China MORE said in Fort Mill, S.C., late Thursday evening, according to MSNBC.

“You turn on the TV and you see a leading presidential candidate saying profanity from a stage,” Marco RubioMarco Antonio RubioTrump may intervene in Pentagon cloud-computing contract: report Trump administration denies temporary immigrant status to Venezuelans in US Colombian official urges more help for Venezuelan migrants MORE, another GOP contender, said the same day in Okatie, S.C. "Profanity from a stage. All these things undermine what we teach our children.”

Trump has repeatedly vowed he will “bomb the shit” out of the Islamic State in Iraq and Syria as president. He recently sparked outrage for echoing a supporter who called Cruz a “pussy."