Immigration to Sweden has been high since world war two, first refugees from the war, then (rough immigration history) finnish, yugoslavian and italians during the 50ies and 60ies to man the growing industries, chileans during the 70ies, iraqis and iranians during the 80ies, yugoslavians and somalians during the 90ies, and iraqis during the 00ies. I would say that Swedish society today is far more accepting of diversification of culture then Sweden in the 50ies (when it was apparently common behaviour to stop, stare and possibly point if a brown person walked down the street).

Sverigedemokraterna has been slowly rising since a meek start in the early 90ies. I would couple their rise with the economic policy of unemployment (standard neo-lib package) that Sweden has followed since the 90ies crises. Until 1990 Sweden had a policy of full employment, so refugees found jobs quickly and by that found a way into society. After 1990 refugees - being low on contacts - has had a hard time finding jobs and has tended to cluster even more to earlier groups of immigrants from similar culture - as there is where their only contacts are. With unemployment also among white people comes the need to blame. Accepted blaming has in particular been directed at young people (lazy) and sick people (faking), while the Sverigedemokraterna is targeting muslims (I remember when they hated black africans most of all, and arabs (as they were known then) were considered almost-european) with all the usual stereotypes.

Essentially an institutionalised unemployment is not only wasteful but also needs someone to blame, so unemployed young white males are easily steered towards blaming the foreigners. It is all about MUD:

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MUD (the moral underclass discourse), SID (the social integration discourse), and RED (the redistribution discourse)

This also fits neatly with why Sweden is late with this development, permanent unemployment was not established here in the early 80ies but in the early 90ies. We are ten years behind on the curve.

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