The party is hardly "radical" by any standard means of measure, and there is not a single indicator that population growth in Stockholm will come to a halt. You're merely making the mistake of assuming that others are like you.
What standard means of measure are you referring to exactly?
I guess time will tell, but if you look at statistics many country side smaller cities are growing when in the past they were shrinking for a really long time. The wind is vänding.