Going on the BNP's history both as a party and that of its members then even if you don't feel you are racist, you're supporting racism and therefore probably a big fat hairy racist by default.
A great uncle of mine was always a staunch lefty, ex miner, lives in a now deprived area and has seen his community die... he's also witnessed a massive influx of people who obviously have no long generational links to South Yorkshire, given that a lot of them a brown, he's put two and two together and come up with an incorrect answer, the ethnic influx has actually SAVED his town. I do sympathise with him, living in a once proud hard working town and seeing it die and become forgotten, he fought in the second world war and what he has seen over the last 60 years MUST be depressing.
So if he voted BNP, I'm not sure I'd call him racist in its purest sense, but incorrect and supporting racism. He doesn't vote red any more, would never vote blue because he remembers the riots, I'm not sure what he votes for but I'm sure there are many in his position who've voted BNP out of sheer frustration, and in these areas the BNP make promises that could be hard to resist for some. I do find it more sad than angering that many pretty decent people feel so forgotten, so depressed at what they see everyday that they'd even contimplate BNP.
Until other parties address these peoples valid worries and feelings, I fear the BNP will thrive. So rather than dismiss them as racists I think all parties should be listening to them and trying to offer them some real hope.