US Election 2016: Mitt Romney's savage attack on 'bully' Donald Trump may backfire on Republican establishment

In a stunning eruption of disgust, disbelief and disapproval, Mitt Romney, the failed nominee from 2012, begged his party yesterday to dump Donald Trump before he makes it all the way to becoming its standard-bearer this time around, excoriating him as a “conman” and a “fake”.

Delivering a searing and highly personal broadside against Mr Trump – whose endorsement he sought and eventually won four years ago – Mr Romney said he was neither jumping into the race nor endorsing anyone.

Instead, he made the case, without explicitly saying it, for a brokered Republican convention in July to confer the nomination on one of the other three runners.

“Think of Donald Trump’s personal qualities, the bullying, the greed, the showing off, the misogyny, the absurd third grade theatrics,” Mr Romney said. “We have long referred to him as “The Donald.” He’s the only person in America to whom we have added an article before his name. It wasn’t because he had attributes we admired.”

While clearly speaking for a large number in the establishment wing of the party who fear that Mr Trump is taking so wide a lead in the nomination scramble, his barely restrained attacks will have backfired if they only infuriate and further galvanise his many millions of supporters. “If you’re Trump, this is like getting the good kind of Kryptonite,” Republican strategist Doug Heye said.

Rather than turning a spotlight on the flaws of the candidate, Mr Romney may instead only have put the flailing dysfunctions of his own party on display. That it couldn’t find a more credible spokesman to make the anti-Trump case also may not have helped.

“Donald Trump is a phoney, a fraud,” Mr Romney said in Salt Lake City. “His promises are as worthless as a degree from Trump University. He’s playing the American public for suckers.” He said Mr Trump’s economic ideas would plunge America into recession and his foreign policy “bombast” was already mortifying America’s allies.

He spoke hours before what promised to be another critical candidates’ debate in Detroit last night prior to Tuesday’s Michigan primary, which, according to polls, Mr Trump should win easily. Due on stage with him were Senators Marco Rubio and Ted Cruz, of Florida and Texas, and Ohio Governor John Kasich. Not taking part was Dr Ben Carson, who is expected to end his campaign today.

While no one in the party has yet said who is the best alternative to Mr Trump – most in the establishment cannot abide Mr Cruz, while Mr Rubio has only won one state – the prescription offered by Mr Romney was for voters to back all three of the other candidates where they can, especially on 15 March, when Mr Kasich must hold his own Ohio and Mr Rubio will defend Florida.

That way, Mr Romney was implying, there remains some chance of denying Mr Trump the simple majority of delegates he will need to be automatically declared the nominee at the party convention in Cleveland in Ohio, opening the way for “a brokered” outcome, which would essentially ensure a furious fight on the convention floor (and behind the scenes) to create a majority for one of the other men.

That, though, is an ugly outcome, likely to trigger a rebellion from the millions embracing Mr Trump and his promise to overturn Washington. But an Associated Press count yesterday showed that while Mr Trump has been racking up victories in different states, he is winning only about 46 per cent of the delegates, falling short of 50 per cent plus one he would need in Cleveland.

Another assault on Mr Trump came in the form of an open letter written by 70 conservative national security experts deriding his positions on everything from trade, his proposed US-Mexico wall, his plan to deny entry to Muslims, and questioning his suitability to be commander-in-chief.

“Mr Trump’s own statements lead us to conclude that as president, he would use the authority of his office to act in ways that make America less safe, and which would diminish our standing in the world,” the signatories wrote, among them Robert Zoellick, a former World Bank president.

In the meantime, an outside political action group, Our Principles, dedicated purely to derailing the billionaire’s candidacy, begun airing searing anti-Trump TV spots in several key states and said it was digging deep into his record to discredit him with voters. “We have a lot more new research, which voters do not know about,” Tim Miller, its spokesman revealed. “This guy can be stopped.”

Mr Trump, who was campaigning in Maine, which votes this weekend, was reliably dismissive of all the attacks. “Mr Romney is a stiff,” he told NBC News, while gleefully reminding followers of Mr Romney’s record of electoral failure.

Some of the more pointed critiques of Mr Trump offered by Mr Romney concerned his statements on bringing back torture and killing the family members of terrorists.

“He cheers assaults on protesters,” Mr Romney said. “He applauds the prospect of twisting the Constitution to limit First Amendment freedom of the press. This is the brand of anger that has led other nations into the abyss.”