We have right wing parties that are the equivalent to the Republicans (though it should be said that even our right-wing parties are usually more left-leaning than the American equivalents; comes with having been a Socialist nation for so long) - but Sverigedemokraterna aren't just a right-wing political party. They're far right extremists, with members who literally used to be Neo-Nazis. Like, shaved heads and swastikas. When they first got into parliment, images got leaked to the press of one of their MPs at a Neo-Nazi meeting, dressed in a Hitler Jugend-uniform - brown shirt and all! - and heiling towards the camera.
Before the party polished up their rethoric and got into parliment and pretended to actually care about politics beyond "deport all immigrants!", their political pamphlets used to talk about the horrors of white Swedish women having children with men of colour, and how this destroyed the purity of the Nordic race. One of their local politicans in the south of Sweden actually wished, out loud, that she could stand on the bridge connecting Sweden and Denmark with a submachine gun and murder immigrants. This ain't your garden-variety "shut down the borders"-right-wingers - these are the "Hitler did nothing wrong"-right wingers.
Sweden has a long-standing problem with Neo-Nazis - Stormfront, Svenska motståndsrörelsen, Nordfront, etc., etc. - but in the last decade, they've started gaining real, political power, and that scares me witless.