Dear white supremacists...

Okay, I lied. This isn't a letter to white supremacists, it's about them. Because their entire game plan is to be the voice for a privileged, self-righteous community of bigots.

So the less you listen to them the less power they have. However, this doesn't mean they should be left in peace.

The racism that counts in South Africa is structural racism. White people have hugely skewed economic clout - our prejudices have impact.

Take Cape Town's top chop, mayoral committee member for safety and security JP Smith, who was apparently cool with the R7-million spent on toilets around Cape Town Stadium for the World Cup, while the budget for new toilets in informal settlements this year is allegedly R20-million. To denormalise privilege we need to expose these decisions at every turn.

The problem is that relative white wealth and black poverty have become everyday ideas so we don't see the insanity in front of us. The most outrageous prejudice becomes acceptable, and asking for common sense to prevail starts sounding radical.

Take talk radio. The overriding social agreement is that everyone should have a say and we should all cumulatively take the outcome of this "debate" as reasonable.

This belief in equality is classic liberalism because it assumes everyone has the same resources (time, airtime, access to public platforms) and therefore the same voice. We don't, and pretending that we do allows the debate to be severely skewed in favour of those with resources.

The consequence is that we can have someone texting Radio 702 or CapeTalk to say shack dwellers should build their homes further apart to avoid fires, and that they have no respect for people who don't look after themselves (true story).

You know how much choice people in shacks have over where to live.

In this case, host Redi Tlhabi and a few callers came down heavily on this imbecile. The trouble is that for the most part media platforms do not reject such madness. They want to seem open-minded, and think everyone should have a say. As a result the debate is often profoundly anti-poor and, in turn, structurally racist.

Take Steve Hofmeyr, a successful white entertainer who tweeted the other day: "Sorry to offend but in my books blacks were the architects of apartheid. Go figure."

Of course we all went at him, reinforcing the profile he needs in the conservative and nostalgic community that pays his bills.

Hofmeyr can say what he wants, but his sponsors should be taken to task for their tacit support. For example, in a few weeks Hofmeyr will appear at the Afrikaans is Groot festival sponsored by Land Rover and Pick n Pay. Are these brands okay with being associated with an apartheid denialist and white supremacist?

Corporate South Africa never had to explain its collusion in apartheid so the least it can do is refuse a platform to its most prominent denialist.

We called on Hofmeyr's bakkie sponsor, Williams Hunt, to recall its vehicle in the light of his bigotry, and it did so.

People running media need to be far more assertive about how they handle the blatant racism that gets aired, and radio presenters should expose caller bigotry far more assertively .

• Koch is a ventriloquist and comedian. This piece first appeared on www.conradkochblogspot.com. Follow him @conradkoch