It is easier when that is the zeitgeist. If every other country in Europe has the same thing going on, it becomes easier to campaign on that sort of stuff. Suddenly the extreme parties don't seem that extreme, and people start to question whether or not previously extreme opinions are that extreme anymore.

Not so extreme anymore. Extreme was the status quo.

Even Sweden has introduced a new law against misbehaving immigrants (before you'd be risking your job just by speaking about the issue) just few days ago - https://www.reuters.com/world/sweden-passes-good-behaviour-l...