The racist rhetoric that extends all the way to the top of the AfD shows that one must assume that an attitude is prevalent - not just in the grassroots, but also among party leadership - that is not consistent with the basic values reflected in our constitution.

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.

I find it surprising, however, that many German politicians generally oppose referendums, but then when it's an EU matter, they immediately scream for a plebiscite.

Germany is not a fair country. Millions of people believe that things aren't fair in this country. Company profits and bonus payments have increased at the same rate as precarious employment situations.

Trump believes politics is a staged fight. But it is not. Still, clear words are sometimes needed in politics. In that sense, I believe I am better than Mrs. Merkel.

As a party of labor, the SPD must work together with the unions to ensure that people can make a living with their work. That is why I am not a proponent of the concept of unconditional basic income. I am, however, very much in favor of decent wage agreements, secure and lasting jobs, employee participation in decision-making and the examination of the social justification for claims and payments.

Donald Trump is betraying everything that made America great: tolerance, democratic institutions and respect for the individual. In that sense, Trump is the most un-American U.S. president that the country has had in a long time.