Well isn't alliansen the only ones who are open to work together with SD in some cases? I mean look at them as a whole, even if Centern don't have a solution themselves doesn't mean it's gonna have much impact on the rest of them (like M, KD etc). They work as a team not individually.
And besides that, there's more to politics than immigration, only some politicians want to make it sound like the one and only big issue we got is migrants. It's not that easy, and if we got rid of all refugees, the big city people will still not give a shit about the countryside, there's more important questions worth bringing up to the spotlight