Rubio celebrates at his caucus-night party. Photo: Pete Marovich/Getty Images

For anxious members of the Republican Establishment, Donald Trump’s failure to win Monday night provided the first sign in months that reality might return to a race dominated by the reality-TV star. Marco Rubio’s surprisingly strong third-place finish — he trailed Trump by just one percent — strengthened the emerging consensus that the Florida senator will be the one party elites can rally around. “The Washington Establishment’s only chance at a candidate now is Marco Rubio,” a top GOP consultant said. “The only thing that stops Trump or Cruz is a winnowing of the field.”

It says a lot about this year’s upside-down Republican primary that coming in third in Iowa is a victory. But, according to GOP insiders I spoke to Monday night, Rubio’s bronze-medal finish behind Ted Cruz and Donald Trump makes him the victor in the race to break out of the crowded Establishment pack. Having survived his immigration war with Cruz relatively unscathed, Rubio may be emboldened to take on Trump. According to a source close to the campaign, Rubioworld is now arming itself for an assault on Trump. “They’ve done a lot of oppo research. Personal stuff,” the source said. “It’s going to be personal to Trump because they know Trump will be personal to Marco.”

Over the coming days, there will be a behind-the-scenes lobbying effort by Rubio’s camp to convince major donors supporting his rivals — Chris Christie, John Kasich, and Jeb Bush — to rally behind Rubio for the battle against Cruz-Trump. “There is major pressure being brought to bear,” one conservative financier said. Christie and Kasich are both running low on cash, and anything but a top finish in New Hampshire spells doom for their campaigns.

The central front in this donor war is the fight over Jeb Bush’s vast fund-raising network. Rubio himself seemed to be speaking to Bush’s backers during his concession speech Monday night. “They told me I needed to wait my turn, that I needed to wait in line,” he said in Des Moines. “But tonight, tonight here in Iowa, the people of this great state have sent a very clear message. After seven years of Barack Obama, we are not waiting any longer to take our country back.”

Rubio’s rising fortunes will amplify the criticism that the pro-Bush super-pac Right to Rise is sabotaging the Establishment’s chances by spending millions attacking Rubio when it should be blitzing Cruz and Trump. “It’s insanity!” former Mitt Romney strategist Stuart Stevens said. “If the purpose of Right to Rise is to run a campaign and not to settle grudges, they have to do that.” Another GOP strategist said, “There will be a hue and cry in the Bush constituency to attack Trump, regardless if it’s a kamikaze mission.”

As the race moves to New Hampshire, however, Bush shows no signs of heeding these calls. “Most people think Jeb is dead. But his ground game in New Hampshire is bigger than Rubio’s, Kasich’s, and Christie’s,” a Bush donor said. “He has all his marbles on New Hampshire.”