On 9 June 2011, Newt Gingrich's campaign manager and half a dozen senior aides resigned en masse, citing "differences in direction" with their candidate. Politicians and pundits queued up to declare his campaign for the 2012 Republican presidential campaign "over".

Fast-forward seven months. Newt is now the only GOP candidate who can beat the front-runner, Mitt Romney, having won a decisive victory in the bellwether state of South Carolina on 21 January, amassing 40 per cent of the vote, and with polls showing him in the lead in the swing state of Florida. Some Republican voters are said to be excited at the prospect of bombastic Newt tearing shreds off Barack Obama, whom they hate, in the presidential debates.

“Conservatives . . . are saying, 'Let's nominate Newt because for four and a half hours of debates with Barack Obama - he'd be the best,'" one of America's leading conservative commentators, George Will, told ABC after South Carolina. "You're talking about giving a guy nuclear weapons for eight years perhaps."

So, just what should we know about Newton Leroy Gingrich?

1 His congressional career ended in failure
Newt is best known for having been Speaker of the House of Representatives between 1995 and 1999. Right-wing Republican voters adored his tax-cutting, welfare-slashing, anti-crime "Contract With America" and his shutdown of the federal government in 1995 and 1996. But it all backfired and he resigned in 1998, having failed to impeach Bill Clinton and remove him from office, and after one of the worst-ever midterm election results for the Republicans.

In a television interview on 22 January Chris Christie, governor of New Jersey and one of the Republican Party's most popular figures, let rip against Newt's record. "He was run out of the speakership by his own party," he said. "This is a guy who has had a very difficult political career at times and has been an embarrassment to the party . . . I'm not saying he will do it again in the future, but sometimes past is prologue."

2 He has issues with ethics
One of the "embarrassing" episodes referred to by Christie relates to Newt's finances. During his speakership, a record 84 ethics charges were filed against him, and in 1997 he was reprimanded by colleagues on the floor of the House of Representatives and ordered to pay a fine of $300,000. It was the first time in the 208-year history of the House that a Speaker had been disciplined for ethical wrongdoing.

Newt likes to claim that the charges were a partisan attack on him by opposition Democrats; yet the House voted against him by a margin of 395-28. It was a bipartisan decision - and the special counsel to the House ethics committee concluded that the man who now wishes to be president had violated tax law and lied to the investigating panel.

3 Family values aren't his strongest suit
One of the most remarkable features of the Republican race so far has been the way in which the party's voters, especially ultra-conservative, evangelical, female voters in South Carolina, have turned a blind eye to Newt's long history of infidelity. He is, after all, a serial adulterer. He cheated on his first wife with the woman who became his second wife, and on his second wife with his third. According to his former campaign treasurer L H Carter, Newt said of his first wife, Jackie (with whom he decided to discuss divorce terms while she was gravely ill and recovering in hospital from surgery): "She's not young enough or pretty enough to be the wife of the president. And besides, she has cancer."
Newt's second wife, Marianne, claimed this month in an interview with the Washington Post that he had asked her for an open marriage in which she would share him with his mistress. As Speaker, he had an affair with Callista Bisek, a congressional staffer, while he was trying to impeach Clinton over his affair with Monica Lewinsky. (A straight-faced Newt later claimed his infidelity was "partially driven by how passionately I felt about this country".)

Does such hypocrisy matter? "[Newt] believes that what he says in public and how he lives don't have to be connected," said Marianne Gingrich in August 2010. "If you believe that, then yeah, you can run for president."

4 He is the perfect demagogue
Newt's strategy for securing the 2012 Republican nomination seems to be a shameless replay of the party's infamous "Southern strategy", popularised by Richard Nixon - that is, exploiting the racism and bigotry of some Southern white voters, as well as their fears of lawlessness and "big government". So he angrily denounces Washington "elites" and the mythical "liberal media", fearmongers about the rise of sharia law, and still sees reds under Democrats' beds. (In 2010, Newt published a book entitled To Save America: Stopping Obama's Secular-Socialist Machine.)

At a debate ahead of the South Carolina primary, he attacked the CNN presenter John King for asking him about his infidelity. To loud cheers from the conservative studio audience, he said: "I am tired of the elite media protecting Barack Obama by attacking Republicans."

Meanwhile, his constant - and factually inaccurate - refrain that Obama has put "more people on food stamps than any other president" helps conjure up negative images of a racial minority - specifically African Americans, as does his call for children from poor neighbourhoods to get jobs as janitors.

He is always keen to highlight the president's "otherness". He has denounced his "Kenyan, anti-colonial" world-view, has said that Obama is not "normal" and has declared that he does not want to "bloody [Obama's] nose. I want to knock him out."

5 He is the master of the U-turn
In 2004 the Democrat John Kerry acquired a reputation as a "flip-flopper", but the shoe fits Newt much better. Despite courting the anti-government, far-right Tea Party and claiming the support of Sarah Palin, Newt has backed measures that Palin-style conservatives say they despise: Obama-style health-care reform, comprehensive immigration reform, bank bailouts and subsidies for prescription drugs.

Over the past year, his very public U-turns and voltes-face have startled even the most cynical pundits. Take the war in Libya. On 7 March, Newt told Fox News that, if he was pre­sident, he would instantly and unilaterally "exercise a no-fly zone this evening", on the grounds that "slaughtering your own citizens is unacceptable". Yet on 23 March, after Obama did precisely as he had suggested, the former Speaker switched his position. "I would not have intervened," he told NBC. "I would not have used American and European forces."

6 He is neither an insurgent nor an outsider, but the ultimate Beltway insider
Newt has spent four decades in Washington, DC as a legislator - and lobbyist. He first ran for Congress in 1974; he served on Capitol Hill from 1979 to 1999 and as Speaker for four of those 20 years.

Since leaving politics, he has "consulted" for various corporations and institutions, including the government-backed mortgage lender Freddie Mac, reviled by Republicans for playing a pivotal role in the sub-prime crisis. Gingrich, who initially claimed he had worked as a "historian" for the firm, ran a consultancy that was paid $25,000 a month by Freddie Mac in 2006.

The inconvenient truth is that he is a long-standing member of the Washington elite against whom he constantly rails. Or, in the words of the conservative columnist Jonah Goldberg: "Gingrich has eaten from just about every trough imaginable inside the Beltway."

7 He makes George W Bush look like a peacenik
Neoconservative Newt pushed long and hard for a war with Iraq. Soon after 11 September 2001, he proclaimed that "if we don't use this as the moment to replace Saddam after we replace the Taliban, we are setting the stage for disaster".

These days his focus is on Iran's nuclear programme, which he hyperbolically describes as a Nazi-like "mortal threat". He supports the murder of Iranian nuclear scientists and has declared that America has "to take whatever steps are necessary to break its [the Iranian government's] capacity to have a nuclear weapon".

He is more belligerent, more dangerous even, than Dubbya. President George W Bush appointed John "Bomb Iran Now" Bolton as his ambassador the United Nations - but Newt has promised to make Bolton his secretary of state.

8 He is not just a hawk but a chicken hawk
Ron Paul, the anti-war congressman and a rival of Newt's for the Republican nomination, has repeatedly called him a "chicken hawk". "I think people who don't serve when they could and they get three or four or even five deferments . . . they have no right to send our kids off to war," said Paul during a debate in New Hampshire.

Newt got married at the age of 19 after his first year at university and quickly became a father; he then avoided the Vietnam war draft by staying on at college after his undergraduate degree to study first for an MA and then for a PhD. "Given everything I believe in, a large part of me thinks I should have gone over," he conceded in an interview in 1985, then added defensively: "Part of the question I had to ask myself was what difference I would have made."

9 He is the Likud Party candidate
As a sop to pro-Israeli Christian evangelicals, Republican candidates have fallen over each other to pledge their unconditional support for the Jewish state, but Newt has gone furthest.

Interviewed by the Jewish Channel, a US cable TV station, last December, he sparked outrage in the Middle East by referring to the Palestinians as "an invented . . . people".

The Arab League described his comments as racist; the pro-western Palestinian Authority premier, Salam Fayyad, pointed out that "even the most extremist settlers of Israel wouldn't dare to speak in such a ridiculous way".

Newt has been a personal friend and ally of the Likud leader and current Israeli premier, Binyamin Netanyahu, since his days as House Speaker. "I see myself as in many ways being pretty close to Bibi Netanyahu in thinking about the dangers of the world," he said in the TV interview. "So I see a much more tougher-minded [sic] and much more honest approach to the Middle East in a Gingrich administration."

For tougher-minded, read "bloody", and for "more honest", read "one-sided".

10 He isn't a popular politician
Right-wing Republicans like him. The rest of America doesn't. A recent CNN poll found his approval ratings stand at minus 28 per cent.
After becoming Speaker, Newt quickly established himself as one of the country's most reviled public figures - and became an electoral liability for the Republicans. According to the US online magazine Salon, he was the target of an astonishing 75,000 Democratic attack ads ahead of the 1996 congressional elections. "The more most people see of him," concluded Salon's Steve Kornacki, "the less they like him."

Or, in the words of George Will: "All across the country this morning people are waking up who are running for office as Republicans, from dog-catcher to the Senate, and they're saying, 'Good God, Newt Gingrich might be at the top of this [presidential] ticket.'"

The party elite - politicians, pundits, pollsters - want Romney as the candidate; but the base, if the conservative state of South Carolina is anything to go by, wants Gingrich. "He will destroy our party," says the Republican congressman-turned-cable news host Joe Scarborough. "He will re-elect Barack Obama, and we'll be ruined."

So perhaps we should all root for Newt.