Every political party, and I would go as far as to say every organization, has its own associated group of violent extremists. That is just the way it is - some people are attracted to anti-social behavior, and what ideology they chose to clothe their deeds in is more coincidence than anything else. What we can choose to do is to either actively fight them, or not - in which case we either passively or actively encourage them. The Sweden Democrats have, by constantly promoting a us-against-the-world agenda, by having people like Kent Ekeroth and others like him in their ranks, by constantly lumping muslim terrorists with ordinary muslims, by allowing racist rhetoric, made their choice - and it wasn't to actively fight the extremists. The Sweden Democrat party leader Jimmie Åkesson's "please don't hurt us"-speech[b] makes it clear that he either just doesn't get it or doesn't want to get it.