It's a sad fact that when people struggle, for example economically, it is very easy to rile them up against any group which is percieved as outsiders. It happends time and again. Racists and nationalists prey on desperation, they don't offer up solutions but they are great at pointing fingers and humans are *really* good at negativity.
You do need to look at the fact that at least in sweden, what this party is saying about immigrants and percieved outsiders etc would fit right in with a lot of the rightwing republicans in your state or national seats.
The scale for left and right and extreme views is very different depending on nation. The US doesnt have any nazis in government like greece has managed after their country essentially went bankrupt, but your right wing extremist politicians in the republican party would fit right in with many of what are considered very exteme elements over here.
It's difficult to simply make a straight translation of extreme left and right wing from europe to the states, let alone a psecific nation in europe and the US.
"Conservative" in the US right now is mainly on economic issues, and most social issues have to do with forcing reliegon down peoples throughts, but they are a shade of who they were as much as 20 years ago. None of these issues, most european conseratives wouldn't touch with a ten foot pole.
While there are obvious racial undertones, American conservatives are color blind compared to european ultra-nationalists.
The US of A is the only civilized country on earth which ignores its own immigration laws, publicly.
You can compare how the US treats hispanic immigrants with how Europe treats Roma and Middle Eastern immigrants.
I think it was 1/3rd or 2/3rd of hungarians that despise jews. There's a political party in extreme Hungary that wants to put a list on all jews in Hungary like they did before the holocaust in Europe.
Problem is when political parties like this gets popularity, another famous party will take their ideas. However, Sweden does a good job not making an alliance with the nationalists, whereas Hungary follows the step Germany took in the 1930s.
I think USA has strictly parties that have strict ideas and dont take from others to make their party "citizens favour". I really don't think there are alliances in USA, but I could be wrong. Sometimes democracy can be a good thing, but it's not when citizens in a country becomes racist.
I do not know about Sweden, but I remember pretty well when in Spain we had a rise of ultras in the nineties. Skin heads. There was not a big party behind this, maybe, those skins were supported by an small ultra nationalist insignificant party fraction we had, but basically, they were independent, organizing themselves in small group of teens, who preyed on immigrants and homeless people, beating them up Clockwork Orange movie style. That movement was somehow extended, but the skins seemed to quit the movement the moment they reached their early twenties.
I think that was a reaction to the first wave of immigration we had. For a country used to "export" people, like we were, it was a surprise to receive foreigners. If you combine the fear to the unknown to the economic crisis we were having then
I think is a natural reaction. It is Ok?. No, not at all, but it happens. In crisis times, the tendency is to blame foreigners, but hell, foreigners came because there were jobs, jobs that the Spaniards did not want to do themselves, but jobs after all