"We didn't mean that kind of Brexit" say Daniel Hannan and Andrew Lilico in response to May's anti-immigrant proposals. To which we Remainers reply: if you ride a tiger, you shouldn't be surprised when it bites you. As I wrote before the referendum:

some of you have a vision of a Britain outside the EU that is a free, liberal socialistic country. These are ideals with which I have sympathy. But we are kidding ourselves if we think a vote for Leave will be a move towards such a society. Instead, it'll be a mandate for Farage and the inward-looking, reactionary mean-spirited philistinism he embodies.

But was my reasoning sound? It might not be.

I say this not because of Daniel's claim that Leavers were motivated more by a desire to reclaim sovereignty than to cut immigration: many wanted to take back control precisely because they wanted to cut immigration, whilst others just can't articulate why they want sovereignty.

Instead, there might be an error here: the association fallacy. Wasn't I trying to discredit decent Leavers like Andrew and Daniel by association with indecent ones?

Let's assume I were. Was this necessarily a bad thing?

Sometimes, we can reach the right decision because errors cancel out. For example, the erroneous belief at the roulette table that red is on a roll can correct the error that "black must be due to come up next". Or mental accounting can protect us from spending too much through weakness of will by putting some money off limits. In similar fashion, I was trying to use the association fallacy to counter what I saw as wishful thinking by free market Leavers.

But there's another defence of what I was doing. It's that the association fallacy might not actually be a fallacy. It's only one if it commits the sampling error.

Let's take a clear example of the fallacy: "You shouldn't be a vegetarian. Hitler was a vegetarian!" This fails because of the sampling error: the vast majority of vegetarians are not genocidal maniacs. But what if a disproportionate number were? Wouldn't this be at least a clue that there might be something wrong with vegetarianism?

In the case of Brexit, the fact that a disproportionate* number of bigots were on the Leave side wasn't just diagnostic of something wrong with the Leave case. It was also causal. The association of the Leave cause with anti-immigration sentiment invited the government to become hostile to immigrants. Yes, Daniel and Andrew claim that Ms May's inference is mistaken. But this doesn't acquit them of the charge of wishful thinking: it is naïve to hope that governments will do the right, liberal thing.

If you think this is another post about Brexit, you'd wouldn't be wholly right. When Nick Cohen and James Bloodworth attack Corbyn and the far left for being pro-terrorist and anti-west they are asking me the same question I asked Andrew and Daniel: aren't my ideals tarnished by association with some bad characters? And the answer is along the same lines. It depends upon proportions: how many such characters are there, and how much power do they have to pervert my intentions?

I don't know how to answer that. My point is instead merely the trivial one that in a second-best world of bounded rationality and bad people, there becomes much more to politics than simply asserting one's ideals.

* In saying this, I'm not claiming that all Remain voters are pro-open borders: they are not.