Having been knocked from his front-runner perch, a fiery Jeb Bush lashed out at Republican rival Donald Trump on Thursday as the former Florida governor fights to energize his stalled campaign and stop the billionaire businessman’s summer surge.

Bush’s name recognition and money — see his recent $100 million-plus fundraising haul — have kept him near the top of the Republican pack, where he has saved his most aggressive criticism for Democrat Hillary Rodham Clinton for much of the year. Now slipping in the polls, Bush abruptly changed course over the last 24 hours, following some Republican competitors who acknowledge Trump has become a serious threat that must be dealt with head on.

“There’s a big difference between Donald Trump and me,” Bush declared in New Hampshire on Thursday. “I’m a proven conservative with a record. He isn’t.”

He charged that Trump “proposed the largest tax increase in mankind’s history” and previously supported partial-birth abortion. “I’ve never met a person that actually thought that was a good idea.”

Bush continued: “He’s been a Democrat longer than being a Republican.”

The comments represent a sharp shift for Bush that underscores a larger political reality.

He has succeeded in raising far more money than his competitors, yet seven months after first signaling serious interest in a White House bid, the former Florida governor has yet to resonate with the vast majority of the GOP electorate. His polling numbers are stagnant, he faces continued questions about his family connections, and influential GOP activists remain skeptical of his conservative bona fides.

“I’ve never met a single grassroots voter who supports Jeb Bush,” said Mark Meckler, a co-founder of the tea party movement.

If there is any solace for Bush’s team, it’s that he’s not alone.

Virtually every candidate not named Trump has suffered in recent weeks as the New York businessman caught fire with frustrated voters and sparked an anti-establishment backlash.

Perhaps no one’s standing has fallen further than Wisconsin Gov. Scott Walker, once considered a top-tier candidate and now languishing in the middle of the pack. Libertarian hero, Kentucky Sen. Rand Paul, is in danger of missing out on the next primetime debate, as is New Jersey Gov. Chris Christie, a former GOP powerhouse reduced to little more than an afterthought amid Trump’s rise.

Trump isn’t taking the pressure off his rivals.

“I don’t see how he’s electable,” Trump said of Bush Wednesday night in New Hampshire, later describing him as a “low-energy person” who has trouble getting things done.

Bush’s team downplays any serious concern, noting that his poll numbers are “steady,” he hasn’t yet begun spending money on advertising, and that most voters aren’t paying serious attention six months before the first votes are cast.

“Having a steady vote share in New Hampshire the summer before the primary is a good place to be,” Bush spokesman Tim Miller said.

“Jeb’s been working his tail off meeting voters, campaigning the way New Hampshire voters expect,” he continued. “As we get into the fall and winter and people actually start making their decision and the paid element of this campaign begins, that’s going to pay dividends.”

Bush may have created more problems for himself this week, however, while trying to capture some of the enthusiasm created by Trump’s immigration rhetoric, including his calls to end birthright citizenship.

Bush said he believes there should be greater enforcement against pregnant mothers who cross the border to have children who then gain U.S. citizenship, referring to those children as “anchor babies.” Facing a Democratic-fueled backlash, Bush defended his use of the term Thursday, but stressed that he believes people who are born in the country should have American citizenship.

Beyond his new battles with Trump, Bush has consistently faced questions from voters who are skeptical of putting a third Bush in the White House. At his Thursday appearance in Keene, a voter told Bush that his brother “won’t even eat Bush beans.”

The same day, another sign emerged that Bush’s family will be a backdrop of his entire campaign, as George W. Bush sent out a fundraising appeal on his younger brother’s behalf. Asked if that conflicts with his characterization that he is his own man, Bush snapped back.

“Is that a contradiction?” he said. “I’ve got my own record. I’ve got my own life experience. I’m blessed to have a brother that loves me and wants to help me, over and out.”

(AP)