Donald Trump Hammers Chris Christie

(CNN)Donald Trump trained his eyes Monday on a surging Republican rival in New Hampshire, Chris Christie, using a newspaper's backing of the New Jersey governor to lacerate Christie's economic record.

Trump leads the GOP field comfortably in the first-in-the-nation primary state, but on Monday took his first shots at Christie, who potentially threatens Trump's dominance there. The comments in Nashua came as Trump escalated his war with Joe McQuaid, the publisher of New Hampshire's largest newspaper, the Union Leader, which has endorsed Christie.

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Trump continued direct attacks against the newspaper's publisher Tuesday evening, tweeting "Shows how dumb Joe McQuaid (@deucecrew) of the dying Union Leader is to put out the letter I wrote saying why I didn't do his failed debate!" And "Joe McQuaid (@deucecrew) of the dying Union Leader wanted ads, lunches, donations, speeches from me, and tweets---very unethical."

Telling the crowd about his personal relationship with McQuaid, Trump said he felt spurned by McQuaid for his biting front-page editorial on Monday. Trump said McQuaid had asked him to express support for letting Christie into a premier GOP debate -- which Trump did -- and that he tried to convince Trump to attend his August Republican forum.

"You don't go try and hurt somebody that's been helping you," Trump told an approving crowd, brandishing a paper copy of the Union Leader that he would soon after throw into the crowd in disgust.

McQuaid was, Trump said, a "low life" and a "sleazebag." But his harshest criticisms were lodged at his Christie, whose "lapdog" in his view is McQuaid.

He dredged up memories of Christie's memorable physical embrace of Barack Obama in the days before Election Day 2012. He recalled the downgrades to New Jersey's credit rating since Christie became governor. And he alleged that it was impossible that Christie did not know about his scandal over the George Washington Bridge that scared donors away from the once front-running establishment governor.

"Does anybody believe that? Honestly?" Trump asked his crowd. "Is there a 1% chance?"

Christie himself has not been implicated in the "Bridgegate" scandal, though several former gubernatorial aides have.

The Tri-State area Republicans have had a relatively friendly relationship on the campaign trail, with Christie declining to get suckered into the daily verbal wars against Trump, which have engulfed other GOP campaigns. But Trump seemed itching for a fight on Monday, as Christie slowly mounts a challenge to Trump in the Granite State.

"The taxes are through the roof," he said of Christie's Garden State record.

"I don't call it a hug. I call it a hug mentally," Trump jabbed at Christie's photographed embrace of Obama shortly after Hurricane Sandy. "It was unbelievable. He was like a little boy: 'Oh, I'm with the president,'."

"I know you're happy he's up here," Trump said of Christie, who has staked his campaign on a strong showing in New Hampshire and has been there more often than nearly any other candidate. "But, you know, the people of New Jersey want to throw him out of office.