Protesting against what may I ask? Why are people voting for an anti-EU party that supports immigration control and not the Greens, Respect or even the good old Labour Party?
The opinions polls show that after the economy the second most important issue affecting people's lives is immigration and border control. Until the mainstream political parties, especially those on the left, wake up to that fact and do something about it then UKIP's support will continue to grow.
The Romanians and Bulgarians haven't even arrived on mass yet. After 1st January that will become as big an issue of not bigger than when the Poles arrived on mass.
The mainstream political parties burying their heads in the sand over these issues isn't going to wish them away.
It isn't just the UK either. There has been a wave of anti immigration parties having success in France, Holland, Switzerland, Austria, Denmark and Sweden. Time the political mainstream woke up to the fact.
The media and their mass hysteria about these immigrants is the main reason for that. Promoting xenophobia is always a good way to get people to buy newspapers. To paraphrase: Lies, damned lies and what you read in the tabloid press.
There have always been protest parties in the UK, the Lib Dems pretending they're a legitimate part of the Coalition has removed the biggest protest party as an outlet. That said, the biggest source of UKIP voters is disillusioned Tory voters who think that voting UKIP will actually achieve something when what it really means is that they're going to most likely ensure that the Labour Party gets a nice majority at the next general election! That really makes me think positively about the UKIP share of the vote