The main problem with UKIP is that people too quickly bring up the whole race and nationalism thing. Their far bigger problem is the fact that that is their sole issue. They don't have any other concrete policies - Farage says one thing; the BBC ask the person in the party actually responsible for that issue and they have to clarify that Farage may have misspoke.
Like when they gained council seats a few years ago. After those elections, my gran (a long-serving Tory Councillor) said she didn't understand why anyone would vote UKIP to their town or county council. Councils sort out bin collections and things like that, not the immigration policy for the country. Then she told the story of how a local councillor had to step down because he printed a cartoon of a Muslim being spit-roasted over a fire.