Via Marginal Revolution, an interesting piece of social science on which factors predict anti-semitism in a sample of British voters. The authors found anti-Semitism to be most associated with: "ethnicity, support for totalitarian government, belief in malevolent global conspiracies, and anti-hierarchical aggression."
By "ethnicity" they mean a belief that to be British you should be born in Britain, white, and Christian, which I would call "ethno-nationalism"; they say their sample doesn't include enough non-white people to draw any conclusions about them.
Interesting about how they measured support for totalitarian government:
Totalitarianism scale was designed in order to measure sympathy for a totalitarian style of government among activists of the extreme left and right, with regard to such matters as the treatment of political opponents; it does not ask respondents for their view of actual totalitarian regimes, but instead elicits respondents’ agreement or disagreement with statements which reflect the kinds of arguments used to justify totalitarian political systems without reference to any specific ideology, such as ‘To bring about great changes for the benefit of mankind often requires cruelty and even ruthlessness’.
More or less, their conclusion is that anti-Semitism is associated with a lack of trust in others, an angry attitude toward authority, and a belief that those in power mainly represent others and are out to get "us."
This finding adds nuance to ongoing debates about whether antisemitism is more prevalent on the political right or left, by suggesting that (at least in the UK) it is instead associated with a conspiracist view of the world, a desire to overturn the social order, and a preference for authoritarian forms of government—all of which may exist on the right, the left, and elsewhere.