Jeb Bush is still being boosted by his $100 million-plus PAC. | Getty Bush: I've got the 'you-know-what' to go after Trump

Jeb Bush has a message for Republican leaders worried about a circular firing squad in South Carolina: Chill.

The former Florida governor is looking to drown John Kasich with Obamacare and is stomping on an already wounded Marco Rubio over his readiness to be president. That won't sit well with a party establishment worried that whoever emerges from that three-man scrum will be too battered to take on a candidate they can't stomach: Donald Trump.


But Bush says he has plans aplenty for Trump, too: "I’m the only guy who’s got the you-know-what to go after him," Bush said.

And as for the attacks on his establishment rivals, he says he's doing little more than drawing legitimate philosophical contrasts. If they sting, well, "It's not bean bag," he said in a phone interview Wednesday night, tweaking those begging the establishment candidates to put their faction first.

The establishment fear is partly rooted in a memo the Bush camp circulated late Tuesday detailed lines of argument against Kasich and Rubio that ultimately characterize them as unprepared for a national campaign or to vie seriously for the presidency. And Pro-Bush super PAC Right to Rise is reportedly dumping millions more into the state to pad an already extensive ad buy there.

And therein lies both the strength of the Bush camp and the danger he poses to all the candidates around him: The $100 million-plus PAC is a financial leviathan, giving Bush's team all the funding it needs to go hard after his establishment rivals but still have plenty left to train on those running in neighboring campaign lanes. Perhaps more than anyone else still in the race, Bush has the financial muscle to take aim at everyone simultaneously.

His rivals seem to have gotten the message that the intensity has elevated. They spent Wednesday clobbering each other and foreshadowing even more attacks.

In a fundraising email, Cruz accused Trump of "trying to burn down everyone and everything in his path."

Trump said he was disappointed that Kasich had attacked him in a recent ad, a complaint that usually precedes a relentless response. "It was a false commercial," Trump said. "I thought it would be, you know, somebody else. But it wasn’t. It wasn’t. It was John, so perhaps we have to take a little tougher stance than I would have normally.”

Bush is also on guard for attacks from Rubio, who employs several senior campaign staffers from South Carolina. His campaign circulated a memo Thursday morning, warning of "questionable tactics" they expect from the Rubio team — and they point to a mailer circulated by a pro-Rubio super PAC that features Bush's mother, Barbara, saying, " We've had enough Bushes."

All the Republicans will get a chance to make these attacks face-to-face Saturday night, when a smaller Republican field — sans Chris Christie and Carly Fiorina — meets for a debate.

So far, however, it's Bush who has charged hardest into South Carolina, where his campaign is banking on a dominant performance to deprive Kasich — this week's surprising second-place finisher in New Hampshire — from going on a winning streak. Bush is counting on the Palmetto State to rewrite the narrative of the GOP primary, which so far for him has been a decline from front-runner to frequent punch line.

To help, his close ally South Carolina Sen. Lindsey Graham has been taking potshots at his rivals all week. "I don’t think he’s prepared to be commander in chief," Graham said of Cruz in an interview Wednesday. "I think his inexperience and his libertarianism won’t play here."

But most of Bush's focus Wednesday was on Kasich's 2013 decision to expand Medicaid under Obamacare, a bitter battle in which Kasich took extraordinary maneuvers to outwit his Republican-led legislature.

The move brought billions of federal dollars to Ohio to cover hundreds of thousands of low-income residents. His move drew the ire of conservative groups that have suggested expansion is an unaffordable boondoggle that ultimately will leave states on the hook when the feds stop paying bills

After largely ignoring the issue in New England, Bush suddenly can't stop talking about it. Though Iowa and New Hampshire both expanded Medicaid with Republican support in recent years, South Carolina is the first state on the calendar that resisted.

"This was a de facto endorsement of Obamacare," he charged. Though other Republican governors made similar choices, including Nevada's Brian Sandoval and New Mexico's Susana Martinez, Bush said Kasich stood apart, though, because of his moral position on the issue. "He makes it sound like he was doing this — like somehow you’re not supportive of your faith if you don't expand Medicaid," Bush said. That argument may resonate with South Carolina Gov. Nikki Haley, who's been rankled by Kasich's religious argument on the issue.

Kasich's team, anticipating the attacks, painted Bush as hypocritical, noting that the cost of Bush's Medicaid program in Florida soared at a much faster clip than in Ohio.

That defense aside, senior campaign advisers for Kasich — who claimed his strong finish in New Hampshire meant "the light overcame darkness"— say they’re counting on an even more visceral scrap between Bush and Rubio to turn off South Carolina voters. They're hoping that feud between the Floridians will nudge voters toward the upbeat message that Kasich says helped him stand out in New Hampshire.

Bush told POLITICO that despite the emphasis on his fellow governor, he intends to continue going after Trump — the poll leader in South Carolina so far. Though he's been singled out for his hits on Rubio and Kasich lately, Bush said he still ended up talking mostly about his complaints about Trump at his most recent town hall event in South Carolina.

"Everyone obsesses about all this stuff," he said, noting that he spent about 90 percent of his comments talking about his own policy ideas. "The rest was all on Trump. I’m the only guy doing it. I find it remarkable. "

Bush continues to insist that he'll support whoever is the Republican nominee, should he not win the primary — and he said his rivals are people he respects "in most cases."

Asked whether that meant there was a particular rival he didn't respect, Bush replied, "Yep" and ended the call.