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DEVELOPING STORY: New Jersey Gov. Chris Christie on Friday endorsed businessman Donald Trump for the Republican nomination for president, becoming the New York billionaire’s most noteworthy endorsement to date.

The endorsement was announced at a news conference in Fort Worth, Texas.

“We don’t need any more of these Washington, D.C. acts," Christie said."We don’t need Washington politicians to come in and fix it."

Christie used the platform to both endorse Trump and attack Marco Rubio for what he sees as the freshman senator's lack of experience.

Christie said no other candidate is better prepared to provide the United States with strong leadership both at home and around the world. He also said that no other Republican candidate is a more formidable challenger to Hillary Clinton.

“I can guarantee you that the one person that Bill and Hillary don’t want to see on that stage in November is Donald Trump,” Christie said.

Christie's endorsement comes the day after a heated Republican debate where both Sens. Marco Rubio and Ted Cruz attacked Trump.

Both Rubio and Cruz fought hard to throw Trump off his stride as the field charges into the all-important Super Tuesday contests. Rubio, in particular, was unrelenting in keeping the pressure on Trump Thursday night, going so far as to claim if Trump hadn’t inherited money he’d be “selling watches in Manhattan.”

Christie attacked Rubio 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."

The announcement comes days before the pivotal Super Tuesday primaries and caucuses.

“I will lend my support between now and November in every way possible,” Christie said.

Christie said he was not offered any position by Trump and intends to serve out the remainder of his governorship in New Jersey and eventually work in the private sector with the hopes of one day making more money than his wife, who works as an investment banker.

A senior adviser to Rubio is interpreting Christie's endorsement as a remedy to what he calls the billionaire's inability to articulate his policy plans, explain why he won't release his tax returns and defend his past financial dealings.

Todd Harris told reporters traveling with the Florida senator that, "Donald Trump can't put a coherent noun and verb together to explain any of these things, so he had to bring in someone like Chris Christie to try to do it for him. And Chris Christie has got his work cut out for him."

Clinton, for her part, said she is eager to debate any Republican on economics and health care policy.

Campaigning Friday at Atlanta City Hall, Clinton talked about the job growth that took place during the administrations of her husband and President Obama.

She compared that to "trickle-down economics" of Republican administrations. And she mocked Republicans for voting repeatedly in Congress to repeal the Affordable Care Act.

She says "they never really tell you what they're going to put in its place," because "they know we won't like it."

The Associated Press contributed to this report