Judging by the responses on The Telegraph's "Your View" section to a question about what would convince people to vote UKIP it would seem that quite a few people have already decided they are going to switch from Cameron's Conservative party to UKIP. Whether they actually do (or can - maybe there won't be a candidate in their constituency) is another matter, but the vast majority of responses do suggest that there is a real possibility that UKIP will be able to present a major challenge to the dominance of the Tories in right wing politics.
Of course this will mean that the right wing vote will be split further and increases the likelihood of Labour returning to power at the next election. In fact, one poster on the Telegraph site actually raised this as a concern as if this should convince disaffected conservatives to vote for Cameron! Yeah, right. Why should we vote for a man who despises us and never misses an opportunity to criticise the things we believe in? I will never ever vote for a party led by Cameron or any one of his cronies. I don't think I'm alone in that opinion.
In my view, the UKIP strategy - along with continuing to develop new and credible policies (not just anti-EU rants) - is to start to attract defections from the Conservative Parliamentary party. I'm sure there must be a few Tories in Parliament right now who are unhappy with where Cameron is taking their party. If UKIP can convince one or two of these to defect to them then others will follow and so will their support.
The Tory party is dead. It just doesn't know it yet. Soon, many Tories will start to realise this and then we will see the defections increase and the agony of watching the Conservative Party destroy itself will finally be over.