New Jersey Gov. Chris Christie is endorsing Donald Trump in the race for the GOP presidential nomination.
Christie said at a news conference in Fort Worth that Trump "will do what needs to be done to protect the American people."
Christie also slammed Florida Sen. Marco Rubio, saying "We don't need any more of these Washington, D.C., acts."
Christie memorably attacked the freshman senator at the final Republican debate before the New Hampshire primary, tripping up Rubio in a moment that likely contributed to his poor performance in the state's primary. Christie accused him of parroting the same talking points repeatedly and said a president should be able to think on his feet.
The endorsement from Christie comes the day after Rubio changed tactics in Thursday's GOP debate and began to attack Trump on a variety of fronts, from his business background to his preparedness to lead the nation. Rubio continued on Friday morning, calling Trump "a con artist" during a round of morning television interviews.
Trump says Rubio is a "desperate guy" and said, "I don't think he's of presidential caliber."
Christie received a thundering reception an hour later as he took to the stage in front of thousands at a convention center.
"I want Texas to be Trump country on Tuesday," the New Jersey governor told the crowd.
Trump said he and Christie had decided to keep the endorsement secret until announcing it Friday and described it as "sort of a shocker." He said the surprise from reporters was clear when they walked into a pre-rally news conference to announce Christie's backing.