Without its members UKIP has and is nothing. There and very, very few 'tribal' UKIP supporters, there are several issues that unite different large groups of UKIP supporters, but it is only the return of power from Brussels to the UK that truly unites all of them.
UKIP has to follow its members wishes, as they will have few qualms about leaving if they don't like the way the party is heading.
This is in strict contrast to the Labour and Conservative parties, who have vast assets both tangible and intangible. They also have millions of tribal voters - people who will support them and vote for them purely because of their name, regardless of their actual policies. These tribal voters are people who are loyal to the very institutions themselves (while I think such blind loyalty is stupid and dangerous, that doesn't change the fact it exists).
The Liberal Democrats are a bit in the middle, they have some such loyalty to their institution/name - but it isn't so ingrained - just look at their current collapse with their policy of supporting(?!) the conservatives in government, and backtracking on their tuition fees pledge - that has done them huge damage - much of it probably permanent.
Labour and Conservative leaders can set policy and their tribes will follow. Liberal Democrats also to an extent. UKIP, nope - policy has to reflect what the members want.
Ultimately this is a good thing, as it is reflected in the UKIP policy towards democracy - a commitment that governments should represent their peoples wishes, governments are not there to act like monarchs dragging their 'subjects' into pointless wars and into bankrupting vanity projects at the whim of some 'great and glorious leader' with his/her eye on their place in the history books.
If UKIP is a party of democracy when we oppose the European Union and its anti-democratic nature, then we must also be a party of democracy in our domestic affairs.
Why do I write this now? Oh yes - because the subject of the union and devolution is raising its troublesome head - any fix is going to be messy to implement, so ultimately it has to be for the people to decide, and when it comes to the crunch it is the peoples wishes that UKIP will support.
If anyone wants their view to prevail, don't try to foist it on the public by getting the party to back it, you need to persuade the public to back it. Then direct democracy will deliver one way or the other.
My view, for what its worth, is that all the British Isles should all be working together as a model sustainable society. We have a perfect geographical position and structure which we are completely wasting.
(NB: UKIP are the fourth largest party in the UK by size of national vote at the 2010 general election; UKIP are the second largest party in the UK by size of the national vote at the 2009 EU elections)