I don't get the argument "that these people aren't racist, but they vote just BNP".
For me, If you vote BNP, you are a racist. I know this is guilt by association but I think it's fair. What's more, making excuses for those who choose to support these hatemongers makes it more acceptable for them to do so.
I know I wouldn't vote for a party when I didn't know their policies and if I did, I'd feel pretty ashamed that I voted without bothering to find out. To be honest, anyone who votes for the BNP and claims that didn't realise they'd just cosied up to facists needs to give up voting for good.