Yasmin Alibhai-Brown: Powell's Rivers of Blood are back again

Back in the spring of 1968, East African Asians were adjusting to the retreat of colonialism. We were, remember, the essential middle-class buffer between whites and blacks, set up to service the empire . East African political leaders were "blackenising" the civil service and other institutions. Asians, born and bred there, found themselves jobless and hopeless.

Those with British passports made arrangements to move to their motherland, a move never imagined by those who handed them citizenship – an act of post-imperial vanity. About 13,000 Kenyan Asians entered the UK to be met by media hysteria to keep back the incoming tides of bituminous "filth". The loyal immigrants were stunned.

The MPs Enoch Powell and Duncan Sandys launched a vicious campaign against non-white immigrants through the early months of 1968. Class snobs both, they became the gentlemen heroes of butchers, bakers and candlestick-makers. Hating the foreigner was easier than hating the toffs who had kept them down.

To curb the racist swell, on 1 March, the Government rushed through an immigration law, described by Auberon Waugh as "one of the most immoral pieces of legislation ever to emerge from any British parliament". Only those with a parent or grandparent born in Britain were thereafter entitled to freely enter.

As Professor Zig Layton Henry wrote in his seminal book on race and politics: "The supporters of immigration controls knew they had the upper hand and they could dictate the political agenda. The temptation to escalate the issue proved irresistible." Powell made his apocalyptic blood and damnation speech the very next month.

Forty years on exactly, I am filled with foreboding as I witness my country giving way again to those contemptible instincts of 1968. Decent Britons collectively fought against Powellian dystopia, tried to forge a nation where various histories and claims would be contested without malice, where race and class, though strong imperatives, would give way to equality and shared humanity. And, in many ways, we did achieve these goals. Britain opened up to difference, most of all at the level of pleasure – food, design, architecture, humour – and intimacy between friends and lovers. Those who came found freedoms and democracy. Other Europeans marvel at this ease of mutual adaptation.

Yet today the air smells of the bad breath of xenophobia and racist bile, on buses, Tubes, radio programmes and the internet, of course. Worse, these attitudes are now considered a valuable democratic indicator – evidence that "alien" immigrants are a disaster for the nation. Intellectuals and the media now treat bigotry with deep respect.

To flag up a BBC season on disgruntled white folk, a trailer shows a white face soiled with graffiti in "wog" languages. Our public service broadcaster is surely inciting racial hatred when it privileges whiteness and seats Nick Griffin of the BNP at the high table of Newsnight? Many of the peeved also hate smoking bans and tough benefit conditions. Those complaints don't produce the rush of sympathy awakened by anti-immigrant invective. Our working classes include millions of black and Asian people too, ignored in this narrative.

Obsessive research into the "dangerous" Muslim men goes on and on and immigrants get trashed daily. Last week John Humphrys repeatedly mugged Liam Byrne, the Immigration minister, with the question: "Are there too many immigrants in this country, yes or no?" Does he seriously think there is such an answer or was he trying to whip up populist anxiety?

Promises made on fair employment have not delivered. Sure there are black and Asian newsreaders and the soaps have opened up but, as Meera Syal and Lenny Henry pointed out recently, British television is adamantly white. As the only non-white, female political columnist, I humbly beg for appearances on our top political programmes. There is only one non-white chief executive officer of a local authority in England – in Ealing. The top companies, criminal justice system and the arts are still unchanged, although they write diversity policies.

Outlandish claims enter the nation's consciousness without challenge. Take the recent Royal United Services Institute report, which reads like the fantasies of a crazed, paranoid mind. Terrorism is caused by "multiculturalism" and the leadership should "lay down the line to immigrant communities". I do believe that multicultural policies have outlived their usefulness and commonalities need to be fostered, but I am aware too that such dire warnings have become a code for Powellite rejection of the multifarious nation, a tough reminder to immigrants and mixed race families that our acceptance is always conditional.

That so many black and Asian Britons dumbly join in these assaults on their own heritage makes me sick. As Hanif Kureishi noted this week: "We have really gone back. I heard someone on the radio saying 'they don't integrate'. Well the Royal Family doesn't integrate, rich people don't integrate, Why is it only Muslims who don't integrate? It is so racist." National identity and welfare state debates are manipulated by influential people to validate the rise of racial resentment against us. When we complain, they say we don't understand, misrepresent their sophisticated arguments. Small brains, I guess. These petty patriots and narrow nationalists have successfully rebranded Powellism and made it cool, cool enough for New Labour, which of course, again surrenders its foundational principles. The Government holds 2,000 asylum and migrant children in detention, some self-harming, others going psychotic. On 15 March, go to London's Young Vic theatre and listen to some of their stories. We deport adults to places we know to be brutal. Unlike in 1968, there are few politicians like Quentin Hogg and Archibald Fenner Brockway who protected the civil and human rights of migrants. Keith Vaz is the exception.

It is our fault too. Muslim politics have savagely wounded the anti-racist alliance. Inter-ethnic culture wars leave us no energy to confront the bigger problems together as we once did. The bombers in London blew up our hopes as well as the nation's optimism. They enable the new racism to feel good about itself.

A Jewish friend prompted this column. She said to me: "I condemn Israeli politics and some things British Jews are up to. But when anti-Semitism seeps through the land, unseen, unacknowledged, I must stand up for my people. You must too. It is your duty. Powell's ghost is awake, Racism is everywhere. I can feel it. Can't you?"