Referendums have always posed a threat when it comes to EU policy, because EU policy is complicated. They're an opportunity for those from all political camps who like to oversimplify things.

Complementing the nation-state as it reaches its limits amid globalization: That is what Europe must offer.

Having a place to live is a fundamental right and the state must establish a framework that ensures that apartments are affordable.

The membership survey was a great moment for inner-party democracy. We can't go back, nor do we want to. Our members are pouring their hearts into this campaign. But people don't join the Social Democrats party just to put up posters. They join because they want to help steer the party.

In 2003, Helmut Schmidt said: Predatory capitalism exists, we have to civilize it and we can do that via Europe. He was right. We haven't tried hard enough.

Referendums are a democratic instrument, but so are decisions reached in a parliamentary democracy. I advise extreme caution when it comes to referendums. In Germany too.

The quota idea is a good one, but there are two problems with it. The first is clear: A quota system would also require all European countries to be prepared to take refugees. And secondly: What happens when the quota has been filled? Would we then simply tell those who are threatened, sorry but we have to send you back?