GOFFSTOWN, N.H. (AP) -- Once a bromance, now a brawl.
Donald Trump and Ted Cruz cast aside any veneer of kindness on Wednesday to trade insults and accusations in a show of hardball politics that demonstrated the stakes for both men in the New Hampshire primary six days away.
The billionaire mogul charged the Texas senator with "fraud" and called for a do-over of the Iowa caucuses. That's where Cruz's unexpected victory exposed weaknesses in Trump's unorthodox, personality-driven bid for the White House.
Cruz shot back with his fiercest attack yet on the man who has dominated opinion polls in New Hampshire, suggesting the reality star doesn't like the reality of losing. He's having a "Trumper-tantrum," Cruz told reporters. "He's losing it."
The back-and-forth between two candidates who once made of a show of their rapport underscored the shifting dynamic in a Republican race rattled by the Iowa results.
Cruz's campaign staff popped champagne on the flight to New Hampshire early Tuesday, proud of stealthily out-organizing the political novice. Trump appeared to take the loss graciously Monday night, but by Wednesday morning he had turned.
"Ted Cruz didn't win Iowa, he stole it," Trump tweeted, and his campaign accused Cruz of dirty tricks in telling Ben Carson's supporters their man was dropping out and they should turn to the Texan.
For all their bluster, the top two were keeping a wary eye on Iowa's surprisingly strong No. 3.
In a blitz of new Hampshire campaigning, Florida Sen. Marco Rubio was casting himself as the sole "unifier" in a deeply fractured party and the man best positioned to beat a Democrat in November.
"When I am our nominee I can bring this party together," Rubio told more than 300 people at an athletic complex in Bow. "We cannot win if we are divided against each other."
For Ohio Gov. John Kasich, New Jersey Gov. Chris Christie and former Florida Gov. Jeb Bush, New Hampshire increasingly looked like a do-or-die proposition: Show some momentum or pack it up. They hustled across the state trying to prevent this from becoming a three-man race.
Christie argued, rather hopefully, that the battle for establishment Republicans was down to him and Rubio.
"He knows we have the best ground game here. He knows we have the most support from folks like this," Christie said.
The long-crowded field continued to shrink.
Rand Paul announced he was dropping out, and that put a new crop of voters up for grabs for the other contenders. The Kentucky senator had tried to improve the GOP's popularity among younger voters and minorities. But his appeal never broadened much beyond the libertarian-leaning Republicans who backed the previous White House bids of his father, Rep. Ron Paul.
Rick Santorum also ended his White House bid and said he will support Rubio. While Santorum is among the nation's most prominent advocates for conservative Christian family values, he struggled for attention in the crowded GOP field.
Trump was far away — in Arkansas — but still getting plenty of attention.
"Based on the fraud committed by Senator Ted Cruz during the Iowa Caucus, either a new election should take place or Cruz results nullified," he tweeted. "Many people voted for Cruz over Carson because of this Cruz fraud," Trump wrote.
Before Trump's tweets on Wednesday, Cruz spokesman Rick Tyler told CNN the senator had apologized personally to Carson, though Tyler said the Cruz team "as a campaign" never alleged Carson was dropping out.
Carson, who is conspicuously absent in New Hampshire, called on Cruz to fire someone on his staff.
"If he does nothing about it that means he agrees with it," he told Fox News.
Cruz offered no apologies. Instead, he declared that his two young daughters were better behaved than Trump.
"I don't know anyone who would be comfortable with someone who behaves this way having his finger on the button. We're liable to wake up one morning and Donald, if he were president, would have nuked Denmark."
Cruz also talked immigration, environment and foreign policy, keeping to the high-octane rhetoric that has made some establishment Republicans recoil.
"We're going to light all their stuff on fire,'" Cruz told a group in Henniker, expanding on his promise to carpet bomb the Islamic State group "into oblivion."
He wasn't the only one unleashing his attention-getting lines. Opening a town hall meeting at a pub in Lebanon, Christie made a striking comparison between Rubio and himself.
"You don't want someone on that stage who looks good in a controlled situation in a TV studio, but when the mud starts to get thrown, all of sudden, looks like a deer in the headlights," Christie said. "You want the old, beat-up, nicked-up pickup truck."
Later Christie asserted he's the best Republican to debate Hillary Clinton because he's a former federal prosecutor.
Referring to the investigation into Clinton's use of a private email server as secretary of state, he said, "She sees a federal prosecutor on the stage, I'll beat her rear-end on that stage."
Bush, meanwhile, told supporters at a campaign stop in Hanover that the next president "needs to be a lot quieter, but send a signal that we're prepared to act in the national security interest of this country — to get back in the business of creating a more peaceful world."
As he paused, one woman behind him appeared to start clapping. To everyone else, he urged, "Please clap."
The crowd obliged.
On the Democratic side, Hillary Clinton and Bernie Sanders tussled over each other's progressive bona fides. The Clinton campaign pushed back against Sanders' assertion that the former secretary of state was a progressive on "some days."
"We've been fighting the progressive fight and getting results for people for years," Clinton said at rally in Derry.
The Democrats are to appear at a CNN town hall Wednesday night.