Obviously, I don't have the right answer because I've been shouting several answers for the last few decades.
I think what is absolutely crucial is that the response is not aimed at defeating the populist. If we did defeat the populist, we would still have that distrust. We would still have that sense that liberal democracy isn't functioning well. The response has to come in strengthening liberal democracy. By definition, if you strengthen liberal democracy, you weaken populism.
How do you do that? First and foremost, you do it by being honest and by accepting that various things did not work perfectly. It is pretty important because in the current anti-populist mode we're in, we have made them the evil ones and us the good ones, as if everything were great before. I think it is crucial that ideology is brought back. People don't just want to know how to make a certain policy. They want to understand why. They want to understand why we have a European Union. Most people are not going to support that just for economic arguments. Of course, if they do, then a great recession is the end of it.
The argument initially was “no more war,” and that has completely disappeared. Similarly, social democratic parties have pretty much given up on the key ideology of international solidarity, and the Christian Democratic party is the same. I think an ideological renewal, as well as an explanation of why we support liberal democracy. The protection of minorities is not about one specific minority. Everyone, at a certain point in time, can and will be a minority and that system will then profit them.
It can only be strengthened through a positive agenda. Let's be frank here. The trust in the system was lost over various decades. It will not be won back by one great PR campaign. It has to be won back by a clear, ideological agenda that is then implemented consistently.