Four years after he was elected as a self-described “hopemonger” promising a new post-partisan era, President Barack Obama is trying to claw his way to re-election with an ugly, divisive campaign in which he is playing the role of fearmonger-in-chief.

On a chilling Wednesday evening in a Las Vegas park, Barack Obama spoke to a raucous gathering of some 13,000 – more than twice the number his opponent Mitt Romney had attracted a few days earlier but a far cry from the crowds of 2008 when he was swept into office with a seven-point victory over Senator John McCain.

With his own star power fading somewhat, Barack Obama had enlisted the help of teen heartthrob Katy Perry to sing before he appeared. Resplendent in a black-and-white latex dress emblazoned with a ballot paper, she delivered five of her pop hits to screams and squeals from the younger attendees.

When Barack Obama finally took to the stage, he began with light-hearted quips about Katy Perry’s 91-year-old grandmother getting lipstick on his cheek and nearly getting him in hot water with his wife Michele.

“I’m just telling you – you might get me in trouble!”

Right on cue, and just like 2008, a woman shouted out: “We love you, Obama!”

He responded, just as he always has: “I love you back!”

But the mood quickly darkened and it was at this point that any comparisons with 2008 evaporated. Barack Obama – who was reading his remarks from two teleprompters flanking the stage – launched into a exhaustive and exhausting diatribe about Mitt Romney.

There was all the standard stump stuff about “Romnesia” – a term dreamt up in the bowels of the Left-wing blogosphere and adopted by the Obama campaign this month as part of its closing argument in this election.

The word is a cute enough campaign term, though perhaps not quite something you would expect from a President of the United States who has been hailed for the world historical significance and beauty of his rhetoric.

Certainly, Mitt Romney is rightly vulnerable on the issue of shifting policy positions. But “Romnesia”, as Barack Obama aides have made clear, is about saying that Mitt Romney cannot be trusted. It’s about calling the former Massachusetts governor a liar.

That’s standard-fare political hardball. But then Barack Obama went a step further. After describing himself as “steady and strong” – words used by his apparatchiks in the post-debate spin room in Florida on Monday – he told the crowd that a vote for Mitt Romney would plunge Americans back to the early 1960s.

“You can choose to turn the clock back 50 years for women and immigrants and gays,” he said.

“Or in this election you can stand up for the principle that America includes everybody. We’re all created equal – black, white, Hispanic, Asian, Native American, gay, straight, abled, disabled – no matter who you are, no matter what you look like, no matter where you come from or who you love, in America you can make it if you try.”

Leave aside for a moment that 50 years ago was 1962, when President John F. Kennedy was in office and it seemed like America was entering a new dawn.

What Barack Obama meant was that Mitt Romney wanted to take away the rights of women and every minority group in the country. He did not say it explicitly – Barack Obama is too clever a politician for that, and the remarks has been carefully prepared before being loaded onto the teleprompters – but he was suggesting that Mitt Romney is a dangerous extremist and very possibly a racist.

Exactly four years ago today in Las Vegas, Barack Obama that “things can get ugly sometimes” in election campaigns and that “say anything, do nothing, do anything” politics can take over.

Barack Obama continued: “The ugly phone calls, the misleading mail and TV ads, the careless, outrageous comments, all aimed at keeping us from working together, all aimed at stopping change.

“Well, you know what? This is not what we need right now. The American people don’t want to hear politicians attack each other. You want to hear about how we’re going to attack the challenges facing the middle class all over the country.”

After resisting for months calls to draw up a plan for a second term, this week Barack Obama tore down a small rainforest by printing 3.5 million copies of a 20-page booklet entitled “A Plan for Jobs and Middle-Class Security”.

But there was nothing new in the booklet and was rushed out just two weeks before election day and the morning after the final debate – too late for Mitt Romney to challenge him on it.

More to the point, Barack Obama’s focus is not on his own record but on tearing Mitt Romney down personally in exactly the way he decried four years ago.

This week, we’ve seen Barack Obama use the softball setting of the Jay Leno Show to denounce Mitt Romney by association based on the clumsy comments of Richard Mourdock, the Republican candidate for the U.S. Senate in Indiana.

Richard Mourdock, asked in a debate about whether a foetus conceived during rape should be aborted, responded that life was a “gift from God” and that “even when life begins in that horrible situation of rape, that it is something that God intended to happen”.

Barack Obama knew that Richard Mourdock was essentially outlining the position of any observant Roman Catholic – that an unborn child’s life was precious no matter how it was created. But Barack Obama told the Leno audience: “Rape is rape. It is a crime. And so these various distinctions about rape don’t make too much sense to me.”

Richard Mourdock – never mind Mitt Romney – made no distinction about different types of rapes or characterized rape as anything other than a crime.

What Barack Obama was doing was what he was doing in his Las Vegas speech – playing on the fears of voters that Mitt Romney is a crazed bigot.

As the laundry list of minority voting groups indicated, Barack Obama was engaging in what one politician described in 2008 as “the kind of slice and dice politics that’s about race and about gender and about this and that, and that’s what Americans are tired of because they recognize that when we divide ourselves in that way we can’t solve problems”.

That politician, of course, was Barack Obama, then running for president.

Barack Obama has signally failed to woo Republicans in Washington and there is precious little evidence he has even tried. Today, we learned that when asked by a Rolling Stone editor whether he had a message for the editor’s six-year-old daughter took the opportunity to describe Mitt Romney as “a bulls***tter”.

Almost all politicians – though not Mitt Romney – swear in private. But for a President of the United States to describe his opponent publicly in such a way was beneath the dignity of his office.

Barack Obama’s tactics in the final days of this campaign might well pay off. Politically speaking, he may not have any other way of scraping a narrow victory – though the risk is that he will turn-off moderate voters.

But if Barack Obama is re-elected the way he has run his campaign may make it almost impossible for him to govern effectively – let alone in the spirit of the “better angels of our nature” that Abraham Lincoln cited in his first inaugural speech and that Barack Obama used to love quoting.

It was John McCain who said in 2008 that he would not “take the low road to the highest office in the land”.

Barack Obama seems to believe that the load road is his only route back to the White House in 2012. It is the kind of strategy that Candidate Obama in 2008 would have viewed as beneath contempt.