For the last time, this is *not* about donations. No party is expected to look clean when they all have to begging for scraps from millionaires. It's about the people that UKIP allows to get into influential positions, time and time again.
People seem to be ignoring this, so I'm going to try running a little thought experiment to try and get the point across. Naturally, this is just a hypothetical and not a prediction so please bear that in mind as you read.
Imagine, just for a moment, that UKIP manages to completely and utterly replace the Liberals as third party. Now imagine that the UK has another hung parliament and UKIP are in the position of kingmaker and able to get some influence. Now imagine that some of the candidates UKIP proposes get their hands close to some of the ministries.
I know this isn't going to happen. And I also know that people who vote UKIP don't vote on the assumption that it will. But just bear with me for a moment and ask yourself if that's really, honestly a theoretical scenario you find appealing or not.
Every single time that a member of the tin-foil-hat brigade comes gleefully bursting out of the UKIP woodwork, the same thing happens. "We don't have anything to do with him." "Oh, we're suspending him." "Don't worry! We're in control of our members." Then before they can finish their sentence another one comes out.
Are people seriously, genuinely, okay with the idea (and it is just an idea) of an organisation so lax and half-arsed about who gets to be part of it getting anywhere near a position of authority? Watch the Marchessini video. There is an influential minority (I mean, presumably, right?) of people in UKIP who will watch that video and wonder why anyone could possibly disagree with such fresh and incisive ideas.
Yes, there's probably some Trotskyists still lurking in the Labour party. Yes, there's probably some archaic old bigots in the Tory party. But the kind of things that keep falling out of UKIP are a) a whole dimension of lunacy away from those and b) not subject to anything like as serious an effort to keep them away from influential positions in the party.