It is impossible to swear an oath to the German Basic Law without realizing that our constitution is among the most liberal constitutions in the world. As the head of government in such a country, I would stand up to all those who call into question this free, open and tolerant model of society.

If we want to create new rules of globalization, then we can't just think in terms of the nation state. The nation state has long offered protection. But it suffers from the fact that many citizens increasingly fear that it can no longer protect them: The threat of transnational terrorism is growing. Freedom of movement rules in Europe facilitate social dumping. Regardless of the make-up of the next government, it must have clear ideas on how to overcome the lack of direction of recent years.

When a man ends up in the White House who boasts about not having a clue and who says that specialist knowledge is elite nonsense, then a critical point has been reached. Then you will have an obviously irresponsible man sitting in a position that requires the utmost degree of responsibility.

There are certain reactions that you aren't allowed to show in Berlin, for example that you feel offended. If you do, the best-case scenario is a sympathetic article along the lines of: Nice guy, but he's not up to it. The alternative is to don a suit of armor and become cynical. But that's not healthy either: Cynicism is the worst characteristic a politician can have. That's why you have to have an internal balance in Berlin, so you can stay true to yourself. And I have that.

Turkey is doing an enormous amount in the refugee question, but it can't continue to pay for everything by itself. That is why we have to talk to Turkey about money.

Europe was founded as a community bound together by solidarity.

CDU head Angela Merkel has tried for years to serve two sides: the conservative side by holding up her CDU party membership. But then at the same time she acts as though she were also a Social Democrat. I don't have this hydra-headed nature. In the end, people will vote for the Social Democratic original.