Pennsylvania: The BNP row feels remote and oddly more unsettling from here; distant thunder portending a calamitous coming one can sense, but not yet quite define. "What's going on, what happened to polite old England?" asks my best friend, a family physician in Pittsburgh, who, like me, is an Asian from Uganda. She is shocked after listening on radio to some of the grumpy old folk from these isles and their practised grievances about immigrants, people of colour, Muslims, white liberals, politicians, and the other usual suspects.

I explain. These punters have lost out as global capitalism sweeps away job security and certainties. Their terror is understandable but not their faith in the Nazi and racist BNP, which promises to vigorously wash off foreign muck and make Britain linen white again.

Once Nick Griffin is in 10 Downing Street, they must believe, Vicky Pollard and Waynetta Slob will at long last run Goldman Sachs, all-night corner shops will be opened by ambitious aboriginal Brits and Prince William will be available to marry the chimney sweep's illegitimate daughter. I mock, but it is only to deflect my own fears of what the future may hold.

When a deep recession combines with legitimised racism, civil strife infects societies with a plague of suspicion and blame. The powerful turn outsiders into scapegoats; and we saw just how with the disgraceful BNP fest on Question Time, on which all political reps enthusiastically showed off their anti-immigrant colours.

This week, Panorama secretly filmed white men, women and, most appallingly, children abusing and assaulting two journalists who pretended to be Muslims living on an estate in the Bristol area. But is the US any better? Or are Americans by inclination self-congratulatory and instinctively down on Europe?

My friend is too often complacent. In her country, over 40 million citizens have no basic healthcare and Hispanic, Muslim and African Americans experience conspicuous racism. Black individuals can rise to the skies, but those at the bottom languish generation after generation. American shock jocks are more toxic than the most outrageously un-PC of British broadcasters and they viscerally hate President Obama.

This week, the right-wing politician and broadcaster Pat Buchanan evoked the same dreams and nightmares as our Mr Griffin – true Americans are white, their land is being stolen from them by Mexicans, blacks and other un-American forces, some now in the White House.

Other raging debates show it is premature to speak of a post-racial US of A. Chris Rock, the African-American comedian, has just released a documentary called "Good Hair", which asks why successful black women including Oprah and Michelle Obama all straighten their hair. Is it cos they want to look more white? I think it is an interesting question. Black women have taken it as an attack. They have hit back so hard, Rock won't walk straight for a long time.

But I also felt a permanent shift in the national psyche away from the US of segregation, lynchings and the Klan. White supremacy is uncool and stupid. Samuel, a 60-year old African-American homeless man, was once on death row, set up by racists for a murder he did not commit. We had coffee sitting on a wall near my hotel. "I know now that America can be a place for someone like me", he said to me, before adding: "I have nothing, but now I can believe. It will never go back. I can die a happy man now. Glad they didn't send me off back then".

A new Gallup poll found that six out of ten Americans believe, like Samuel, that race relations can only get better under Obama. Only 13 per cent are pessimistic. In Britain, meanwhile, even though it has been hugely comforting to watch white Britons recoiling from Mr Griffin, 22 per cent of those polled after his Question Time appearance said they would consider voting for his hate-loaded band, some of whom are violent.

Unlike Samuel, I can't believe or hope the forces of good in the UK can overcome the march of the jackboots. Things can only get worse. Sleepless in Pittsburgh, I struggle with the woeful possibility that my unborn grandchildren may still have to fight to be accepted in Britain. They could move to North America.

Have we wasted all those years, trying to get our adopted homeland to embrace its diverse history and multifarious soul? I fear so, but we soldier on.

y.alibhai-brown@independent.co.uk