Of course it is workable. So far the populists achieved nothing. I gather you are from Germany. So far, AfD achieved exactly nothing precisely because the majority of people still stand firmly against them. And that is a good thing. Do they express opinions which I don't like? Absolutely. Do they have a right to do it? Yes. And it needs to be defended too, whether we like it or not. Such is the nature of liberal democracy we built.
In the US, populists had a run for 4 years and look how much real change they achieved? Not much (well, there are some aspects where I would disagree with myself, but those are relatively fixable things).
I think our societies are proving very resilient. I am confident.