The main lesson from the anniversary of Martin Luther King’s famous speech seems to be that everyone in the world agrees with it and always has done. Sarah Palin said “May his dream become reality”. John McCain and George W Bush made tributes to him, and I expect the ghost of the bloke who shot him said, “He was a great and uniquely wonderful man, a role model for everyone in the world, and as a professional assassin it was an honour and privilege to assassinate someone with as much integrity as Dr King.”

And everyone insists he would have supported what they’re doing now. The anti-immigration, pro-war Tea Party claims Dr King was a conservative who would back them. Fox News claimed that if he was still alive he’d support their campaign against black rap music. Jeremy Clarkson will claim that when King organised a boycott of Alabama buses, it wasn’t because they were segregated but because he knew public transport was rubbish, and he wanted to go everywhere in a BMW 3.0 litre V8 M60.

Psychoanalysts will insist the speech was a call for more people to go into therapy, as his dream of children living in a world in which they weren’t judged by the colour of their skin can only be interpreted as an unconscious desire to drown his father.

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David Cameron praised King’s “visionary leadership”, so he seems to believe it’s in the spirit of such leadership to send vans around inner cities plastered with messages condemning illegal immigrants. Because presumably if Dr King was around now, he’d say: “I know I demanded compassion for all people, but even I draw the line at some bastard poncing off our housing benefits just because his village got burned down in Somalia.”

Politicians and newspapers that condemn immigrants and Muslims for “flooding” the country are full of praise for the “Dream” speech, to the extent that you need to check you heard it right, as maybe he said: “I have seen the promised land, and there’s no bloody Bulgarians in it for a start.”

Maybe David Cameron’s praise for Dr King has signalled a change in direction for the Government. Because Dr King didn’t just speak about segregation, he saw it as part of what he called “the evil triplets of materialism, militarism and racism” and, giving his reasons for opposing the war in Vietnam, said: “We must deal with the deadly Western arrogance that has poisoned the international atmosphere for so long.”

So it could surprise people when the Prime Minister starts his speech about Syria by saying, “We can condemn Assad all we like, but the underlying problem here is deadly Western arrogance. I’ve told Mr Obama, and he spoke at Dr King’s memorial march so I’m sure he agrees.”

Then the politicians around the world who admire King so much might adopt his attitude towards the economy. This didn’t happen at the memorial, at which business leaders spoke, and it was sponsored by a company called BTC Consulting. Maybe they arranged a slogan for the march – “Now your rights are made civil we’ll make consulting bills shrivel.”

It’s a shame they didn’t exploit other sponsorship opportunities, such as getting Kevin Bacon to make a speech that went: “I too have a dream, of a day when children won’t be judged by the colour of their skin, but by the content of their superfast 4G mobile phone, because I may not get there with you, but one day EE will have us ALL connected.”

But the adoration of banks and big business displayed by most Western governments may not fit exactly with the attitude of their hero. For example, he said: “A true revolution of values will soon look uneasily on the glaring contrast of poverty and wealth. With righteous indignation, it will see individual capitalists taking profits with no concern for social betterment, and say: ‘This is not just’.” If you look carefully, you may spot a subtle difference between that and the policies of George Osborne.

The other side to the speech that can get lost is that Dr King wasn’t just hoping for a world in which people were nicer, he was calling for a movement of millions that would force change in the system. He didn’t say he had a dream and it made him feel really chilled, and if anyone else gets stressed about the Ku Klux Klan or not being allowed on the same street as white people they should try dreaming and the tension will simply melt away. He asked his followers to “go back to Mississippi, go back to Birmingham”, and bring about change.

To many this must have seemed an impossible task, given the violence of those who disagreed. The Southern police protected segregationist killers, and the FBI called King “the most dangerous man in America”. (Now they’ll assure us they only kept him under constant surveillance as they always adored him, and didn’t want to miss a word of his inspiring rhetoric).

Maybe what the 50th anniversary of the speech reveals is that politicians are marvellous at standing up against injustice, as long as it was 50 years ago. Ask any political figure about the Spanish Inquisition and they’ll be completely against it, maybe even signing a petition. It’s only when it’s happening now it gets tricky for them. Maybe they’re so overworked, they’re always 50 years behind.