Now it's Marco Rubio versus the governors.
The volatile Republican presidential primary has shifted to New Hampshire where Rubio faces three governors — Chris Christie of New Jersey, John Kasich of Ohio and former Florida Gov. Jeb Bush — determined to take him down next week.
New Hampshire is where the real culling of the presidential field takes place, and it was immediately clear Tuesday that the days of "Iowa nice" campaigning are over.
"Let's get the boy in the bubble out of the bubble, and let's see him play for the next week in New Hampshire. I'm ready to play, and I hope he is," New Jersey Gov. Chris Christie said, referring to Florida's junior senator.
Rubio on Monday night finished the Iowa caucuses in third place, just behind Donald Trump and winner Ted Cruz. His campaign is pressing the message that the crowded primary has now become a three-way race — Rubio against the two anti-establishment Republicans, Trump and Cruz.
"If I'm our nominee we will defeat Hillary Clinton, and it won't be by a flip of a coin," Rubio told hundreds of people packed into Exter's 160-year-old town hall. "When I'm our nominee I will bring our party and the conservative movement together."
With many leaders of the GOP establishment fearing that Trump or Cruz as the nominee could be a disaster for the party, Rubio wants to consolidate political and financial support. But first he has to dispatch Bush, Kasich and Christie, who have devoted considerably more time to New Hampshire than Rubio.
"Each of those (establishment) candidates is an existential threat to each other," said former New Hampshire Republican chairman Fergus Cullen, a Kasich supporter. "They don't have to beat Trump, but they do have to beat each other. None of them can afford to finish behind anyone else in their bracket, setting aside Cruz. Cruz earned a bye week by winning Iowa."
Historically, the establishment favorites win the nomination, and conventional wisdom has long held that governors tend to make stronger candidates than legislators. But the old rules are out the window in this election, with anti-establishment candidates leading and three respected governors struggling for relevance.
Campaigning Tuesday across New Hampshire, Bush and Christie cast Rubio as a Republican version of Barack Obama — a first term senator with zero experience as a chief executive.
"They are gifted in how they speak," Bush, 62, said of Sens. Rubio and Cruz during a stop at Franklin Pierce University. "But what about their life experience? Is there something in their past that would suggest they have the capability of making a tough decision? Is there something that you can look back on and say — whether it's their business career or their political career — that they actually did something that might have been against their own ambitions in order to achieve a public good?"
Christie, 53, was more blunt, calling Rubio a "constantly scripted" flip-flopper on immigration and unprepared to be commander in chief.
"Marco Rubio has been a United States senator for five years and for two of those years he's been running for president," Christie told a packed VFW hall in Epping, predicting that Clinton will be the Democratic nominee. "So you better put someone tough and tested and ready up there or we're going to lose. Or, worse yet, what if we won with somebody who wasn't ready to be president?"
Rubio brushed off the criticism from Christie and Bush in a Fox News interview.
"This is hard. They are working just as hard as I am. They have a right to see it through," Rubio said. "I do think it's time for the Republican Party to begin to coalesce and of course that's what this process is about, coalesce around someone that can win."
In Iowa, Bush, Christie and Kasich received less than 7 percent of the vote combined, compared to 28 percent for Cruz, 24 percent for Trump and 23 percent for Rubio. A super PAC helping Bush spent $14.9 million in Iowa TV ads, according to NBC, which comes to $2,884 per vote.
The goal of the governors vying to emerge as a top choice for mainstream Republicans is not necessarily to win New Hampshire, where Trump has a big lead in the polls, but to finish ahead of Rubio and ideally in second place.
"It's wide open. You've got at least four people that have a shot at it. I wouldn't close it off at all just because Rubio came in third in Iowa. He may get a bounce, he may not. Things move around so much here I'm very cautious trying to predict this far out what's going to happen," said Andrew E. Smith, a nonpartisan pollster in New Hampshire.
One key obstacle, however, could be convincing New Hampshire voters that they are still contenders.
"I like Jeb Bush, and I would love to support him. I voted for his father and for his brother, but I don't want to waste my vote," said Barbara Child, a retired nurse in Manchester.
Allies of the 44-year-old Florida senator want supporters of the more mainstream governor candidates to get behind him as the candidate best equipped to unite the party and go on to win the general election. That message helped him in Iowa, where entrance polls for the news networks found Rubio the strong favorite among caucus-goers most concerned about electability. He won 43 percent among voters who said winning the general election was the top quality they wanted in a candidate.
Conservative Solutions, a super PAC supporting Rubio, began airing a new TV spot pushing that message, too.
"Marco Rubio is the conservative who can win — and the Clinton machine knows it," says a narrator. "Rubio beat the establishment. He'll unite Republicans and restore the American Dream. If you're not with Marco, you're electing the Democrats."
New Hampshire allows independent voters to participate in party primaries, and the state tends to support more moderate and mainstream candidates than Iowa, where evangelical voters dominate the GOP caucuses. That's why Bush, Christie and Kasich have focused far more on New Hampshire than Iowa and why Cruz has never been viewed a strong candidate here. The Texas senator is scheduled to hold a midday rally in New Hampshire today before heading to South Carolina, which holds its primary Feb. 20.
"There have historically been a significant segment of the New Hampshire electorate that are moderate Republicans. The problem that the moderate candidates have had this year is that there are just too many of them," noted Smith, the pollster. "They all have their pluses and minuses. But none are so strong or so weak that they don't have a chance."
The average of recent New Hampshire polls compiled by RealClearPolitics.com shows Trump way ahead with 34 percent support, followed by Cruz with 12 percent, Bush and Kasich with 11 percent each, and Rubio with 10 percent. It's essentially a four-way tie for second place.
Contact Adam C. Smith at email@example.com. Follow @adamsmithtimes.