GOP Candidates Take Aim at Marco Rubio in Debate

With New Hampshire primary just days away, rivals jockey for position; Chris Christie attacks Florida senator.

Florida Sen. Marco Rubio paid the price of a rising profile and poll ratings as Republican presidential rivals pummeled him in Saturday’s debate, just three days before a make-or-break New Hampshire primary.

The hardest hits came from New Jersey Gov. Chris Christie, who savaged the freshman senator as untested and accused him of slinking away from a controversial immigration overhaul.

Mr. Rubio, who has previously defused less biting attacks from his onetime mentor, former Florida Gov. Jeb Bush, seemed less prepared to match Mr. Christie, a dogged former prosecutor, blow for blow.

Saturday’s debate at St. Anselm College in Manchester, N.H., also marked the return of Donald Trump to the stage, but the audacious billionaire was at times overshadowed by Mr. Christie—who, in a more crowded field months ago, was relegated to the undercard debate. Mr. Trump skipped the last debate because he said the Fox News network and moderator Megyn Kelly treated him unfairly.

Texas Sen. Ted Cruz, who tangled repeatedly with Mr. Rubio in the last debate, backed away from confrontations with retired neurosurgeon Ben Carson and Mr. Trump.

The debate loomed as the candidates’ last, best chance to swing a state where 2012 exit polls show nearly half of the Republican primary voters picked a candidate in the last few days. One of the biggest questions in the final days of the race will be whether Mr. Christie’s assault slows Mr. Rubio’s momentum—and if it does, which candidate stands to benefit most from it.

“You have not been involved in a consequential decision where you had to be held accountable. You just simply haven’t,” Mr. Christie said. “The memorized 30-second speech where you talk about how great America is at the end of it doesn’t solve one problem for one person.”

Referring to Mr. Rubio missing Senate votes to campaign, Mr. Christie said, “That’s not leadership, that’s truancy.”

The ganging up on the Florida senator was expected as he has been gaining ground in the polls, drawing boisterous crowds and attracting mounting support from the large donors and elected officials who traditionally side with the favored candidate.

In a sign that he was rattled, Mr. Rubio resorted repeatedly to the same line about President Barack Obama in response to questions about electing another first-term senator without executive experience.

Mr. Cruz has also faced criticism in recent days from Mr. Carson for spreading false rumors that he was quitting the race.

Invoking former President Ronald Reagan’s “11th commandment” not to criticize a fellow Republican, Mr. Carson sought to remind the audience of his status as a political outsider, “I’m not going to use this opportunity to savage the reputation of Sen. Cruz, but I will say I was very disappointed that members of his team thought so little of me…It gives us a very good example of certain types of Washington ethics…. That’s not my ethics.”

Mr. Cruz tried to lay the matter to rest. “When this transpired I apologized to him then and I do so now. Ben I’m sorry.”

Saturday marked the first time the Republican race didn’t include an undercard debate; three of the lower-polling candidates dropped out of the race after weak showings in last week’s Iowa caucus. Also missing was former Hewlett-Packard CEO Carly Fiorina, whose poll numbers rendered her ineligible for the main stage even though she won more votes in Iowa than Mr. Christie and Ohio Gov. John Kasich.

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