Sharpened attack lines and impatience infused the Republican presidential debate on Wednesday. Jeb Bush assailed his onetime protege in Florida, Marco Rubio, over his Senate attendance record, while Gov. John Kasich of Ohio ripped into Donald J. Trump and Ben Carson, calling them unqualified for the White House.
The free-for-all of verbal assaults, including several critiques of the news media, reflected the new volatility in a race that Trump dominated for months. It now appears to be shifting in favor of candidates like Rubio and Carson as the first nominating contests near and voters start paying closer attention to the field.
Rubio and Carson faced the toughest questions but emerged largely unscathed, with Rubio in particular winning strong applause from the audience for his denunciation of negative campaigning. Kasich made a strong impression by showing new aggressiveness, but Trump, bent on recapturing his lead in polls, was more restrained in his mockery of his rivals than he had been in the previous two debates.
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 primary voters in Florida.
"Marco, when you signed up for this, this was a six-year term — you should be showing up to work," Bush said. "I mean, literally, the Senate, what is it, like a French workweek? You get like three days where you have to show up?"
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.
"Jeb, let me tell you, I don't remember you ever complaining about John McCain's vote record," Rubio said. "The only reason you're doing it now is because we're running for the same position and someone has convinced you that attacking me is going to help you."
Bush receded after targeting Rubio, failing to turn in the sort of bravura performance his supporters had hoped for.
Even when Bush boasted light-heartedly about his undefeated fantasy football record this year, the line was hurled back in his face.
"We have $19 trillion in debt, we have people out of work, we have ISIS and al-Qaida attacking us, and we're talking about fantasy football?" Gov. Chris Christie of New Jersey demanded, turning his fire on Bush and the moderators, who had asked about regulation of the fantasy sports industry.
While the debate, broadcast by CNBC, was ostensibly dedicated to the economy, the fluid dynamics of the Republican race — with new polls showing Carson in the lead in Iowa and nationally, and Trump and especially Bush in decline — drove the candidates to seek moments that would emphasize their credibility and electability and resonate with conservative voters who are dissatisfied with Washington and politics as usual.
Several candidates faced tough questioning about their financial policies. Carson defended his plan to radically overhaul the tax system: He has said he would take inspiration from God and push for a "proportional tax system" based on tithing, in which people would pay the same percentage — close to 15 percent — of income in taxes, while deductions and loopholes would be eliminated.
When a moderator insisted that his tax plan would leave the government without significant revenue, Carson pushed back.
"That's not true," he said. "It works out very well."
Kasich was quick to dispute Carson. "This is the fantasy that I talked about in the beginning," he said of Carson's tax ideas. "These plans would put us trillions and trillions of dollars in debt."
Rubio seemed to get the better of Bush again when they discussed their economic plans in close succession. While Bush spoke wonkishly of "the code" and "regulatory cost," Rubio cast the issue in personal terms, saying how tax reform would affect "the guy that does my dry cleaning."
THE EARLY DEBATE: Oh, you again? The four Republican candidates who were banished for the third time to an early evening debate looked like diners at a table in Siberia, straining to make conversation as they looked past one another at what they were missing.
Bobby Jindal, Lindsey Graham, George E. Pataki and Rick Santorum all needed a big moment at Wednesday night's Republican presidential debate to seize voters' attention in a 15-candidate field.
It was unclear if any got that moment, though there were spirited disagreements in a debate focused on the economy and tax policy, and Graham told several crowd-pleasing one liners, including his remark that Sen. Bernie Sanders of Vermont, who is seeking the Democratic nomination, went "to the Soviet Union on his honeymoon and I don't think he ever came back."
All four men on the stage are mired at 1 percent or less in national polls.
At the end of hourlong debate, it was unclear if any of the four were closer to grabbing the attention of Republican voters.