Donald TrumpDonald TrumpPerez and Ellison agree on DNC playing neutral role in primary Ellison: 'Begin investigations' on impeaching Trump Report: House measure forcing release of info on Trump conflicts likely to die in committee MORE is capping off a dramatic day of intense attacks against Republican primary rival Marco RubioMarco RubioA guide to the committees: Senate Schumer: GOP will break from Trump within months GOP loses top Senate contenders MORE with a rally in Oklahoma City, Oklahoma. 

Earlier Friday, the GOP front-runner was endorsed by former White House candidate Chris Christie. The New Jersey governor is expected to stump for Trump in the lead-up to next week's Super Tuesday contests.