Dirty, low-down, mean and cruel ... Get ready for the nastiest Presidential race of all time

Trump began Thursday night’s debate with a stirring defence of his manhood: "He referred to my hands, if they're small, something else must be small. I guarantee you there's no problem.” From then on, he condescended to “little Marco,” even as he came under relentless attack from all sides.

The day had begun with Mitt Romney’s speech at the University of Utah, leaked to the press in advance to ensure that people would see him laying into Trump. It brought to mind Labour Chancellor Denis Healey’s remark that being attacked by his Tory counterpart Geoffrey Howe was like being “savaged by a dead sheep”. Romney, a devout Mormon and father of five clean-cut boys, makes an unlikely attack dog.

The speech was a thorough destruction of Trump’s credentials. Romney called him a “phony” and a “fraud,” and listed a string of failed businesses, from Trump Vodka to Trump Mortgage, Trump Steaks to Trump University. He noted “the bullying, the greed, the showing off, the misogyny, the absurd third grade theatrics” and asked whether voters would be keen to have him as a role model for their children and grandchildren.

“He’s playing the American public for suckers,” Romney concluded. “His domestic policies would lead to recession. His foreign policies would make America and the world less safe. He has neither the temperament nor the judgment to be president.”

We will never know if this sort of withering judgement from a respected party elder could have damaged Trump if it had been made before the first of his primary victories, in New Hampshire. It is certainly too late now. Romney was the definitive establishment candidate, mistrusted by the party’s right wing when he won the nomination in 2012.

Back then, he sought Trump’s blessing, a fact the Donald was not slow to draw attention to. “He was begging for my endorsement,” Trump said, during a rambling response at a rally in Portland, Maine. “I could have said, ‘Mitt, drop to your knees.’”

Although Romney was equally unsparing in his criticism of Hillary Clinton, describing her as “untrustworthy and dishonest,” his remarks about Trump will provide valuable ammunition for her campaign, particularly in Michigan, where Romney’s father George was a popular Governor.

At Thursday night’s debate, Rubio and Cruz called Trump a liar, a con man, and a failed businessman. They mocked his ignorance when it comes to foreign policy and accused him of selling out American workers by having the shirts that bear his name manufactured in China and Mexico. But when asked if they would support him as the party’s nominee, both said yes.

So far, only a handful of Republican politicians have threatened to defect or sit the election out rather than vote for Trump. Nebraska Senator Ben Sasse has said he will leave the party. Virginia Congressman Scott Rigell wrote: “To live with a clear conscience I will not support a nominee so lacking in the judgment, temperament and character needed to be our nation's commander-in-chief.”

In the New Yorker, writer Adam Gopnik compared Trump’s rise to that of French National Front leader Jean Marie Le Pen, who was soundly beaten in the country’s presidential election of 2002, thanks in part to the support of Socialist party loyalists that held their noses to vote for their arch rival Jacques Chirac. How many moderate Republicans, appalled by Trump’s racism and vulgarity, will vote for Clinton?

In his address at the Mar-a-Lago Club in Palm Beach on Super Tuesday, after winning seven of eleven states, Trump claimed that he would expand the Republican party base to defeat Clinton. “I am a unifier,” he said. “I know that people are going to find that a little bit hard to believe, but believe me.”

Then, having realised that by taking questions from the assembled journalists he could get an extra half hour of free publicity, he pivoted to his general election pitch. “The middle-class has really been forgotten in this country. We’ve lost our manufacturing jobs. Millions and millions of jobs… We can’t let it happen,” he said.

“Hillary Clinton doesn’t have a clue… People in the middle-income groups are making less money than they made twelve years ago. And in her speech, she just said they’re making less money. Well, she’s been there with Obama for a long period of time. Why hasn’t she done anything about it?”

Trump has won the Republican nomination on a platform of economic populism that will stand him in good stead in November. He is sharply critical of free trade deals, promises to protect American workers from the effects of globalisation, and says he will maintain Social Security spending and drive down medicine prices - all positions that orthodox conservative candidates cannot and will not take.

The Rust Belt states of Ohio, Michigan, Wisconsin, West Virginia and Pennsylvania are especially fertile ground for this message. In many blue collar, post-industrial cities - Cleveland, Ohio, for instance, where the Republican party will hold its convention this summer - the Great Recession has not ended.

Nationally, unemployment is back down below five percent, but the share of the wealth going to labour has continued its long, slow decline: from 68.8 percent of Gross National Product in 1970 to 60.7 percent by 2013. In 1979, there were 19.3 million manufacturing jobs in the USA. Last year, there were only 12.3 million.

Last September, pollsters at Ipsos asked voters if they agreed with the statement “More and more, I don’t identify with what America has become.” 72% of Republicans, 58% of independents and 45% of Democrats said they did.

Trump points out that Bill Clinton signed the North American Free Trade Agreement and was instrumental in welcoming China to the World Trade Organisation. He observes that Hillary was for the Trans-Pacific Partnership (TPP) before she was against it. Unions have blamed NAFTA for the loss of American jobs, and steadfastly oppose the TPP.

“He’s formidable, he understands voters’ anxieties, and he will be ruthless against Hillary Clinton,” Governor Dan Malloy of Connecticut said. “I’ve gone from denial — ‘I can’t believe anyone would listen to this guy’ — to admiration, in the sense that he’s figured out how to capture everyone’s angst, to real worry.”

Clinton and Trump will be the least popular presidential nominees ever. In a Quinnipiac University poll released last month, 56% of respondents had an unfavourable impression of Clinton, while just 39% viewed her favourably. Trump fared even worse, 59% to 34%.

This has led to much speculation that this year’s presidential election will be the nastiest of all time. Despite the veneer of civility maintained by Barack Obama and Mitt Romney, the 2012 election was spectacularly negative. Of all the commercials run by Obama’s campaign, 86% were devoted to attacking Romney. He in turn spent 79% of his advertising dollars tearing down Obama.

Trump has suggested that Clinton should be in prison for storing classified emails on her private server while she was Secretary of State. He has accused her of lying to the families of dead diplomats about what happened during the attack on the US Consulate in Benghazi in September 2012, and said that Bill Clinton’s philandering is fair game because his behaviour (and Hillary’s defence of her husband) is “demeaning” to women.

Clinton has just as much material to work with, and although she has been trying out some positive lines on the campaign trail - “America never stopped being great. We have to make America whole” - whether or not she can beat Trump may come down to how well she and her allies are able to define him as a racist, sexist, egotistical clown.

In the 1968 presidential election, Democratic candidate Hubert Humphrey’s team ran an advert targeting Richard Nixon’s vice-presidential pick, Spiro Agnew. As a man laughs hysterically, the camera pulls back, revealing a television screen reading “Agnew for Vice-President?” Then the laugh turns to coughing and a message flashes up: “This would be funny, if it weren’t so serious…” Humphrey lost, but it’s not hard to imagine Clinton and her allies trying a similar tack.

Trump might also be vulnerable to a retread of the most famous negative political advert of all, featuring a young girl picking the petals off a daisy before being engulfed by a mushroom cloud. The commercial was deployed in 1964 by President Lyndon B. Johnson’s team to suggest that his challenger, populist Republican Barry Goldwater, could not be trusted with the safety codes for the atom bomb.

Johnson was an unpopular and not particularly charismatic president, having taken over following the assassination of John F. Kennedy, but he virtually swept the board against Goldwater, prompting a major political realignment that gave birth to the ‘Southern Strategy’ and the modern Republican party. Many conservatives fear that Trump will cause a similar schism.

Whether he wins or loses, the election is certain to be ugly. There have already been several violent episodes at Trump rallies, tacitly endorsed if not outright encouraged by the candidate. As security dragged a protester away in Nevada, Trump riffed on political correctness. “There’s a guy, totally disruptive, throwing punches, we’re not allowed to punch back anymore,” he said. “You know what they used to do to guys like that when they were in a place like this? They’d be carried out on a stretcher.”

On Tuesday, video surfaced of a black student, Shiya Nwanguma, being shoved around by a group of Trump supporters led by white supremacist Matthew Heimbach, who is banned from entering the United Kingdom because of his segregationist and anti-semitic views. As Trump’s rallies get bigger and protesters bolder in the run-up to Election Day, there are bound to be further confrontations.

In his speech denouncing Trump on Thursday, Romney evoked the spectre of fascism. “He creates scapegoats of Muslims and Mexican immigrants, he calls for the use of torture and for killing the innocent children and family members of terrorists. He cheers assaults on protesters,” Romney said. “This is the very brand of anger that has led other nations into the abyss.”