One of the wealthiest and most influential Republican donors in the country is throwing his support to Senator Marco Rubio of Florida, a decision that could swing millions of dollars in contributions behind Mr. Rubio at a critical point in the Republican nominating battle.

The decision by the donor, Paul Singer, a billionaire New York investor, is a signal victory for Mr. Rubio in his battle with his rival Jeb Bush for the affections of major Republican patrons and the party’s business wing…

Alex Conant, a spokesman for Mr. Rubio, welcomed the endorsement, adding, “We know we have a lot of work to do before Marco wins the nomination, but clearly this moves us in the right direction.”…

In his letter to his donor network, Mr. Singer described Mr. Rubio as “the best explainer of conservatism in public life today, and one of the best communicators the modern Republican Party has seen. Marco Rubio can appeal to both the head and the heart.”

Singer’s impending decision comes at a potentially pivotal time for former Florida governor Jeb Bush, who is struggling with deteriorating poll numbers and turned in a weak debate performance on Wednesday evening in Colorado. Singer’s move will raise further questions about the effectiveness of the Bush campaign’s efforts to staunch the flow of money and support to Rubio with attacks on his Senate record and whispers about misdeeds in his past. 

Given the timing of Singer’s move, speculation that Bush’s performance in Wednesday’s debate pushed the billionaire hedge-fund magnate into Rubio’s camp will be unavoidable. Bush, who has long promised to run a joyful and optimistic campaign, made headlines in the debate by attacking his one-time protégé for missing Senate votes…

Above and beyond the seven-figure checks he’s capable of cutting to candidates and political-action committees, his endorsement carries sway in the wider community of wealthy Republican donors. He has emerged as one of the biggest bundlers of hard money in the Republican party, raising hundreds of thousands of dollars for Senate candidates in the 2014 election cycle. Over the past several years, he’s united donors who favor an aggressive, internationalist foreign policy — including Citadel’s Kenneth Griffin and AQR Capital’s Cliff Asness — to build a broad fundraising network ​that many say is second only to the libertarian Koch brothers’ in its strength. Singer is also a supporter of conservative think tanks like the American Enterprise Institute and the Manhattan Institute, activist organizations like the Federalist Society, and super PACs like the Club for Growth and Ending Spending. 

For months, Republican donors viewed Marco Rubio as a growth stock. After his bull run in Wednesday’s debate, investors are buying.

It started even before the debate in Boulder ended. Donors who had been getting calls from Rubio’s Colorado campaign chairman for two months were suddenly emailing him. Seven donors he’d been working couldn’t convey their messages fast enough: I’m in.

“The movement in donors and activists is significant and palpable,” said Josh Penry. “People saw Marco last night and they saw a conservative and they saw a winner. The people who always liked him but doubted his polish now see a guy on stage they can see next to Hillary Clinton.”…

“Phones have been ringing off the hook all day,” the campaign official said. “Fundraisers already scheduled are seeing increased attendance—and lots of people want to host events.”

Jeb Bush’s campaign, wounded after another mediocre debate performance, is bracing for the possibility that revenue dries up in the coming weeks ahead…

Staffers in Miami are reportedly frustrated after having relocated there only to be asked now to work for less money and accept reassignments to other states. There is a “broad sense of betrayal, disappointment and anger,” according to a source inside the campaign…

Other campaigns are already positioning themselves to exploit Bush’s decline. John Kasich, who has been treading water, could see an opening among more moderate Republicans as Bush fades. And rival Marco Rubio is courting the establishment donors that originally flocked to the elder Floridian and one-time friend.

Rubio, younger and gifted, provided Bush with help in the state legislature. Bush provided Rubio with donors, endorsements and — at one especially curious moment — a golden sword.

By this week, however, the relationship itself had become a kind of weapon…

“Someone has convinced you that attacking me is going to help you,” Rubio told Bush during Wednesday night’s GOP presidential debate, after Bush had criticized Rubio. The power of the comeback was in its familiarity — in Rubio’s pitying sense that he knew Bush well enough to know Bush had betrayed himself…

“It was a godsend for Marco,” a chance to show off his political talents and get out of Bush’s shadow, all in the same sentence, said Jorge Luis Lopez, a lawyer in Miami who is backing Rubio. “For years, everybody [in Rubio’s camp] always had to validate, ‘Is Marco ready to do it?’ And now, everybody sees Marco is ready to do it. And it came from the lips of his own mentor.”

But it’s worth drilling down on one key reason why Rubio is so effective and dangerous — to his GOP opponents, and potentially in a general election as well. It’s this: Rubio knows how to feed the angry preoccupations of many GOP base voters while simultaneously coming across as hopeful and optimistic…

Bush’s theory of the 2016 race has been that the way to win the White House is to restore hopefulness and optimism to the conservative vision and thus broaden its appeal. This (Bush believes) requires a break with the sort of politicking that is designed to feed the anger and despair of the GOP’s shrinking core voter groups over demographic change, Obama’s transformation of the country into something no longer recognizably American, and so forth. This is what Bush meant when he said the GOP nominee must be prepared to “lose the primary to win the general.” And last night, Bush again gamely made this point, arguing that Americans crave a “hopeful future,” adding: “They don’t believe in building walls and a pessimistic view of the future.”

A lot of conservative primary voters may well hear such talk and conclude Jeb Bush is talking down to them — that he mostly has contempt for their preoccupations and fears. But Rubio has shown an ability to speak directly to those preoccupations and fears while simultaneously sounding the sort of hopeful, optimistic, forward-looking tone that fits comfortably with Jeb’s theory about the need to broaden the party’s demographic appeal.

This isn’t just because Rubio is young and Latino. His formula is a bit complicated. Last night, Rubio, in what appeared to be an appeal to the deep resentment of many of these voters, skillfully converted legitimate questions about his personal financial management into evidence of Democratic and elite media contempt for his relatively humble upbringing, which he proceeded to explain he had overcome through hard work. Rubio’s narrative is both laden with legitimate resentment and inspiring!

Nobody ever accuses Senator Rubio of Elmer Gantry-ism. Why? Because if he is a cynical, calculating performer, he’s a brilliant one. I like to think that I am immune to political oratory, but one does have to admire the way that Senator Rubio can turn on that American-dream stuff like flipping a switch. Shortly after the Gang of Eight immigration fiasco, I saw Senator Rubio face a very, very skeptical audience — with Senator Cruz also on the stage — of conservatives who were practically ready to bear him out of the venue on their shoulders when he was done. He is, as Jeb Bush put it icily, “a gifted politician.”

He is also an apostate on immigration, the issue that has revealed the purported “libertarian moment” of 2017 to be anything but that. Conservatives would be foolish to simply declare anathema upon Rubio for his ill-considered immigration-reform misadventure — he did, after all, walk away from the mess he helped make once it became clear what a dog’s breakfast it was — but they are right in being suspicious of the fact that his first instinct was to make a deal and to be willing to make one that even in the best-case scenario wasn’t very good…

Senator Rubio here has the opportunity to combine good politics with good policy and declare that, should he become president, in his first term action on immigration would be limited to border security and enforcement. If, at the end of four years, he can make a credible case that the border is secure, that we have developed a credible procedure for dealing with visa overstays, and — most critical — that we have a robust system of workplace enforcement of our immigration laws, then in 2021 we might have a reasonable conversation about what to do about the millions of illegals who are here already.

A longtime political advisor to Jeb Bush posted a pair of tweets seemingly warning 2016 rival Marco Rubio that there would be future attacks headed his way.

https://twitter.com/murphymike/status/660195154599415808
https://twitter.com/murphymike/status/660195424788082688

Taking a victory lap in Iowa after a dominant debate Wednesday, Marco Rubio declined to respond to Jeb Bush’s attacks on him during the debate, but told reporters he did not think it was a smart strategy for Republicans to attack one another. 

“I just don’t think it’s a smart thing for Republicans to do Hillary Clinton’s job for her,” Rubio said in a gaggle after his speech at a rally organized by county Republican parties in Northwest Iowa. “One of the reasons I think we lost in 2012 is Republicans attacking each other weakened their eventual nominee.”…

Rubio, it’s true, does not attack Bush directly in his stump speeches. But almost every single one of them includes an obvious jab at the former governor of his home state, usually about how Republicans should not just be electing the person who’s next in line. This evening, Rubio appeared to be making a reference to Bush’s latest “Jeb Can Fix It” tour, which Bush launched following his disastrous debate performance.

“I point out these problems not in an effort to discourage you, but in an effort to remind you that we can fix everything before us,” Rubio said. “There is no problem before America that is not within our reach to fix. But we have to go do it, and we’re running out of time. And we won’t be able to do it if all we do is elect the same people, the next person in line with the same ideas. They’re not bad people, they love America, but the world has changed, and our policies must change with it.” 

The super PAC backing Marco Rubio sees just four candidates having a shot of winning the Republican nomination. And Jeb Bush isn’t one of them.

“When you consider all angles, as we do, we believe there are really only four candidates with a reasonable chance of becoming the Republican nominee: Senator Marco Rubio, Dr. Ben Carson, Donald Trump and Senator Ted Cruz,” Warren Tompkins, head of the Conservative Solutions PAC, and media consultant and lead strategist Jon Lerner wrote in a memo sent out to donors, friends and supporters on Friday.

“And when you look on to the general election against Hillary Clinton, we are convinced that Marco gives the GOP its best chance to win. The Clinton Machine itself openly acknowledges that Marco is the candidate they most fear.”