In the wake of his miserable showing in the Republican debate last week, Jeb Bush rolled out a new and grimly apt campaign slogan on Friday in New Hampshire, the early primary state he probably has to win if he is to have any chance of securing his party’s 2016 nomination. “Jeb Can Fix It,” it proclaims. But fix what? Before he can fix the country, he’s somehow got to fix his own abysmal campaign.

The Bush family political network and the Jeb financial juggernaut, it was assumed, would cow every serious rival. Jeb seemed to think so too. Rarely, though, has a candidate come across as so vapid, and never can one have so utterly misjudged the mood of his party.

Jeb Bush is a nice guy and a serious guy, who once was a very able politician. By common consent, he was a successful governor of Florida, whatever you thought of his policies. Students of his family dynasty will remember that Jeb was the son that “Poppy” – George H W Bush – hoped and believed would make it to the White House, not that feckless rapscallion George Jnr.

Then came 1994. Against the odds “Dubya” won the governorship of Texas, but Jeb was defeated in Florida. Four years later Jeb did make it to the governor’s mansion. But by then the battle of the brothers was over. It was George W, not Jeb, who was vying for the presidency in 2000. The younger sibling’s role was simply to deliver his crucial swing state – which he did, but only just, and with a large helping hand from the Supreme Court.

Presidential prowess? Republican candidates in televised debate Show all 10 1 /10 Presidential prowess? Republican candidates in televised debate Presidential prowess? Republican candidates in televised debate DONALD TRUMP - MOGUL AND PRESENTER Most likely to say: “You other guys are just a bunch of stiffs. I LOVE Mexico. I will make America great again!” Least likely to say: “I invited Hillary Clinton to my wedding. Which wedding? I forget. Pass me a comb.” Reuters Presidential prowess? Republican candidates in televised debate JEB BUSH - FORMER FLORIDA GOVERNOR Most likely to say: “I am the only one with a proven record as a conservative governor.” He will always add at least one sentence in Spanish. Least likely to say: “I know how to campaign. The last time I ran for office? 2003.” Reuters Presidential prowess? Republican candidates in televised debate SCOTT WALKER - GOVERNOR OF WISCONSIN Most likely to say: “I took on the unions and beat them. I won two elections in a Democrat state and a recall election too.” Least likely to say: “Put a guy without a college degree in the White House. I won’t tell you why I dropped out.” AP Presidential prowess? Republican candidates in televised debate MIKE HUCKABEE - FORMER GOVERNOR OF ARKANSAS Most likely to say: “I will fight to end gay marriage and reverse the Supreme Court on Obamacare.” Least likely to say: “You over there, Fox News guy. Keep my seat warm in the studio, because I’ll be back soon!” AP Photo/John Locher, File Presidential prowess? Republican candidates in televised debate BEN CARSON - FORMER SURGEON Most likely to say: “Barack Obama has been a disaster for America and I am the only to have called him out consistently.” Least likely to say: “I have never ever held elected office or even run for one. But I have a great life story!” Getty Images Presidential prowess? Republican candidates in televised debate TED CRUZ - SENATOR FROM TEXAS Most likely to say: “I will end big government and slash Washington to ribbons. Bye-bye gay marriage and Obamacare.” Least likely to say: “Hey, Mr Trump, if you want to play the ‘birther’ game again, I was born in Calgary, Canada!” EPA/SHAWN THEW Presidential prowess? Republican candidates in televised debate MARCO RUBIO - SENATOR FROM FLORIDA Most likely to say: “President Obama is wrong on Iran and wrong on Cuba. I won’t chum about with tyrants.” Least likely to say: “I look like a puppy, but bring it on Putin. Yes, Jeb Bush was my mentor. Who cares?” AP Presidential prowess? Republican candidates in televised debate RAND PAUL - SENATOR FROM KENTUCKY Most likely to say: “Everyone else on this stage is war crazy. I will not send your children to fight pointless wars abroad.” Least likely to say: “Time Magazine called me ‘the most interesting man in politics’ last year. Why y’all yawning?” Reuters Presidential prowess? Republican candidates in televised debate CHRIS CHRISTIE - GOVERNOR OF NEW JERSEY Most likely to say: “I am a two-term governor in a Democrat state with a record of reaching across the aisle.” Least likely to say: “Any bridges in Cleveland I can foul up? Don’t ask me about New Jersey’s economy.” Getty Images Presidential prowess? Republican candidates in televised debate JOHN KASICH - GOVERNOR OF OHIO Most likely to say: “Welcome to my state, where jobs are growing and spending is down. You want to win Ohio, don’t you?” Least likely to say: “Don’t send me any foreign policy questions, because I’m more or less clueless. I might ramble. Again.” AP

However, it has been obvious for ages that the Republican base, those activists who turn out for primaries and caucuses, is not looking for nice guys. It wants candidates who vow to “tear down Washington” – which is why Donald Trump, the retired neurosurgeon Ben Carson, the former Hewlett-Packard chief executive Carly Fiorina, and the firebrand Texas senator Ted Cruz, are combining for about 60 per cent in most polls. Jeb has ambled on oblivious, stuck at single digits in the polls. He’s talked about running “with joy”, promising not to pander to neanderthal conservatives in the primaries – even though every Republican nominee in the past couple of decades has had to do so.

Even Bush père, a gentleman if ever there was one, used to hold his nose every four years and go into what he used to call “campaign mode”, making outrageous assertions about opponents. Jeb, however, doesn’t seem to be able to do “campaign mode” for long. And when he does, it’s clear he hates every second of it.

Ditto the debates. “I’m not good at them,” he freely concedes. “If you want an entertainer [read Trump] I’m not your guy.” Instead, he’s the one on stage with the nice smile and a reasonable approximation of gravitas, who finds it impossible to sneer, Trump-like, at his rivals, or harangue them as does Cruz. Instead he gets mauled by them.

Alpha-male Trump simply bullies Jeb. But not only Trump. Chris Christie, the pugnacious governor of New Jersey, had his best campaign moment so far by wading into Jeb after the latter had given a mildly humorous answer to a question about fantasy sports. “We’re talking about fantasy sports,” Christie erupted, “when the economy is floundering, millions don’t have jobs, and al-Qaeda and Isis [Islamic State] are at the gates?”

Poor Jeb. But even that put-down wasn’t his most excruciating moment. That had come earlier, when Bush half-heartedly attacked his one-time protégé, the young and charismatic Florida senator Marco Rubio, for missing votes in Congress. Crisply, Rubio turned the criticism back on Jeb, who was then left fumbling for a riposte as Rubio rolled right over him.

Ben Carson, Donald Trump and Jeb Bush at the second debate in California in September (AP)

Mere debating points to be sure. But these are the incidents that determine debate winners and losers, who’s on the up and who’s on the way down, or out. Most embarrassing of all, the pupil had humiliated his erstwhile master, in front of a live television audience of millions. Politics is a cruel trade. But it doesn’t get much crueller than that.

And even that’s not the whole of it. When he entered the race last May, Bush was assumed to have the Republican establishment – party grandees, Congressional leaders, big business and Wall Street – all locked up. The nomination battle, it’s been assumed almost from the outset, will boil down to a contest between a champion of the establishment and an outsider: be it Trump or Carson – or maybe Cruz, if voters conclude that a minimum of political experience is in fact required to beat Hillary Clinton.

The debate has only hardened the impression that Rubio is a much better “establishment” horse than Bush. Yes, Jeb has got $100m (£67m) in his political action committee coffers. But that money can’t be used for direct campaign expenses, rather for generic ads. Far more important, on a day-to-day basis, are ordinary donors, whether small ones or the “bundlers” who collect hundreds of thousands of dollars from individuals in their fundraising networks and then give the proceeds to a candidate’s campaign.

Jeb will be able to fix things, but only by running a leaner, meaner campaign - and betting the ranch on New Hampshire <p> </p>

Bush’s own fundraising has already stuttered to the point where he recently had to lay off hundreds of staffers and slash spending by 40 per cent. Now there’s a risk his donors will defect to Rubio. If so, the game will be up. In fact, it may well already be.

Conceivably, Jeb will be able to fix things, but only by running a leaner, meaner campaign, and betting the ranch on New Hampshire, which looks like the friendliest of the early voting states. He’ll surely stick around for a while: Bushes don’t throw in the towel before a vote has been cast. But he comes across as a candidate from a more civilised political era that has vanished.