Candidates show sharper edges in third debate

Sen. Marco Rubio of Florida coolly rebuffed attacks from his onetime mentor, Jeb Bush, and Sen. Ted Cruz of Texas emerged as a champion of social conservatives at Wednesday’s Republican presidential debate, as both men found their voices after months of lower-key performances.

Testiness and sharpened jabs infused the night as struggling candidates like Bush, the former governor of Florida, and Gov. John R. Kasich of Ohio ripped into their less experienced rivals and tried to portray them as unqualified for the White House.

The free-for-all of verbal assaults reflected the new volatility in a race that Donald J. Trump dominated for months. It appears to be shifting in favor of candidates like Rubio and Ben Carson as the first nominating contests near and voters start paying closer attention to the field.

Rubio, a first-term senator, had the best night of his campaign, showing the political talent that many insiders had long seen in him. He and Carson, a retired neurosurgeon now leading in several polls, faced the toughest questions but emerged largely unscathed, with Rubio in particular winning strong applause from the audience at the University of Colorado Boulder for his confident performance and deft counterpunches.

Bush, under great pressure to have a strong debate that would reassure his supporters and change the trajectory of his struggling campaign, had another lackluster night, raising the possibility that uncommitted donors will write him off and embrace candidates like Rubio.

Frustration permeated the Bush camp: Danny Diaz, Bush’s campaign manager, told reporters that he had complained to CNBC, the cable network hosting the debate, that Bush was receiving too few questions from the moderators.

Kasich made a strong impression by showing new aggressiveness from the debate’s first moments, taking on Trump and Carson in hopes of improving his dismal standing in voter surveys. Trump, bent on recapturing his lead in the polls from Carson, was more restrained in his mockery of his rivals than in the previous two debates, and even faded into the background for long stretches.

It was a night that saw a reversal of fortunes: Trump and Bush have been in the campaign spotlight for months as they jousted with each other and asserted their financial dominance in the race, but both were overshadowed Wednesday by the commanding performances of Rubio and Cruz.

Rubio, an ally of Bush when he was governor of Florida and Rubio was the state House speaker, found himself under sharp attack from Bush over his reputation for chronic absenteeism in Washington. Rubio has missed more votes than any other senator this year. Bush, who has fared poorly with voters despite months of campaigning and heavy spending, blasted Rubio over his work ethic — a striking moment in the ongoing fraying of their friendship as they compete for support from moderate Republicans in Florida.

Rubio hit back forcefully, noting that Bush has said he is modeling his campaign after Sen. John McCain’s in 2008, and that McCain missed many votes in the chamber during that run. And he attributed the criticism to the fact that Bush is struggling in the polls.

Cruz also stood out far more than he had in the first two debates, reminding viewers of his fights against Republican leaders and blistering the news media in a fashion that delighted the crowd. He made a strong case for why he could emerge as the candidate of choice for evangelical voters, a vital Republican bloc.

Bush, whose mild-mannered, pragmatic persona and family lineage have turned off many voters, drew little applause as he dwelled mostly on policy and did little to undercut his chief antagonist in the race, Trump, who has repeatedly belittled him. He did not directly take on Trump, saying obliquely and in somewhat rambling language, “It troubles me that people are rewarded for tearing down our country.”