The BNP (and those in small right wing parties like them) provide those on the left with a few services. Firstly they give them the ability to say how disgusted they are by comments or actions (which I know from experience is always good for a few retweets or shares),
|Former BNP leader Nick Griffin is now a voters of the UKIPs.|
The European elections are not carried out on FPTP (first past the post) but the votes for MPs and the majority of AMs are and we just so happen to have Welsh elections coming up in May. In the 2015 general election there isn't a single seat that the UKIPs could have won as a result of knuckle draggers lending them their support. Welsh elections have a much lower voter turnout than the general elections, the difference between the last two was over 23% (65.6% v 42.2%). The turnout for the European elections was just 35.6% which is far closer to the sort of turnout that the Welsh election is likely to receive.
The UKIPs will win seats in Wales. Their worst case scenario would be to win one seat in each of the five regions. They could always win more than one seat in those regions. Their best case scenario will see them winning constituency seats but this does mean they are less likely to win a regional seat that the constituency is part of.
In summary, the UKIPs will win seats in May. Lower turn out will benefit the UKIPs and if the BNP are not a registered party then a lower turnout could mean that BNP voters who vote for the UKIPs could be the difference between UKIP winning seats or not.