Everyone can have racial prejudice, but white people weren't and aren't affected by racism, not in real terms, not in ways that matter, not in the real world.
But that's just not true. Someone noted above, the gangs in Rochdale targeting white girls. Another person noted how their friend's parents disapproved of her for being white. Someone else mentioned a Polish person getting beaten up. There's plenty of anti-white racism and of course it affects people. If you're told you're less than others because of the colour of your skin, that is going to hurt. No matter if someone with the same colour skin as you is prime minister or president.
I think it's fair to say that generally in the UK we've seen a lot more racism against people who aren't white than those who are. But it's wrong to say that white people aren't affected by racism when they experience it. I think it's way more acceptable these days to be racist towards white people - whiteness is used as a synonym for being uncool, horrible, self-centred, etc etc. People seem to think it's okay because black and Asian people have experienced a lot of racism from white people. I think we should be aiming for less racism all around, not more racism against white people to balance things out!