The spectacular collapse of the BNP in recent years has left a lot of racist voters searching for a new home.
While some have switched their vote to other obscure racist parties, many former BNP 'migrants' have moved to support Ukip instead. This has left party leader Nigel Farage with a rather difficult balancing act to perform.
On the one hand Farage's party is not explicitly racist like the BNP are, but on the other hand they do rely heavily on the support of racists. As Farage's reaction to Ukip's recent heavy defeat in Oldham showed, this is support that he not only tolerates, but is also willing to exploit.
This tension was evident today as he took part in his regular call-in show on LBC radio with Nick Ferrari.
One man phoned in to tell Farage that he was "generally quite an admirer of yourself" before going on to ask him how "EU membership [affects] the UK European rape invasion by blacks and Muslims?"
The caller went on: "White demographics and white genocide. How important do you see the issue of white genocide?"
Now most other mainstream politicians would have immediately condemned any caller talking about "white genocide," or at the very least refused to engage any further with them.
Instead Farage began his reply by insisting that he's "a little confused by all this." Now it's not entirely clear what he was confused about. The caller had asked about "white genocide" and a "rape invasion" by "blacks and Muslims". He was clearly a racist, if not a white supremacist. What exactly was there for Farage to be confused about?
"I don't actually think there is anything about this referendum debate that ought to touch on race at all," he continued before adding an inevitable 'but'.
"I will say this to you that I do think that we have seen… what we saw on New Year's Eve… quite a big increase in a variety of forms of sexual violence."
And then another 'but'.
"But I think it's a big mistake to tie that into a black/white argument."
And then another 'but'.
"But I do think that if we are irresponsible and if we allow huge numbers of young males, particularly to come from countries which have different attitudes to women then we are giving ourselves a social problem and we do need to think about it."
Yeah but no, but yeah, but no. By the end Farage had got himself into such a tangle that it was easy to miss just how calculated this answer really was.
On the one hand Farage appeared to be distancing himself from the obviously racist views of the caller, while at the same time saying that his fears of a "rape invasion" by foreigners were justified. It was a classic Farage answer and yet when you boil it down, all it really amounted to was the statement 'I'm not racist, but...'
And herein lays the key to why Ukip have succeeded where the BNP could not. The electoral system and a continuing culture of tolerance means that it is almost impossible for an outright racist party to ever break out of a tiny minority of support in the UK.
However, there is still potential for a party representing the typical 'I'm not racist, but...' voter to prosper. Today Farage showed exactly why he is still the man to hoover that vote up.