COLOGNE, GERMANY - APRIL 22: A protester holds a sign reading "Stop AfD" during a demonstration against the right-wing party Alternative for Germany (AfD) in Cologne, Germany on April 22, 2017. The AfD party holds their party congress on the 22 and 23 April in Cologne. ( Leon Kuegeler - Anadolu Agency )
COLOGNE, GERMANY - APRIL 22: A banner reading " We see what you can't see which is the radical right wing" hangs from a building during a demonstration against the right-wing party Alternative for Germany (AfD) in Cologne, Germany on April 22, 2017. The AfD party holds their party congress on the 22 and 23 April in Cologne. ( Leon Kuegeler - Anadolu Agency )
COLOGNE, GERMANY - APRIL 22: People participate in a demonstration against the right-wing party Alternative for Germany (AfD) in Cologne, Germany on April 22, 2017. The AfD party holds their party congress on the 22 and 23 April in Cologne. ( Leon Kuegeler - Anadolu Agency )
COLOGNE, GERMANY - APRIL 22: People hold a banner reading "Make racists afraid again" during a demonstration against the right-wing party Alternative for Germany (AfD) in Cologne, Germany on April 22, 2017. The AfD party holds their party congress on the 22 and 23 April in Cologne. ( Leon Kuegeler - Anadolu Agency )
COLOGNE, GERMANY - APRIL 22: A protester holds a sign implying "Make love not AFD" during a demonstration against the right-wing party Alternative for Germany (AfD) in Cologne, Germany on April 22, 2017. The AfD party holds their party congress on the 22 and 23 April in Cologne. ( Leon Kuegeler - Anadolu Agency )
COLOGNE, GERMANY - APRIL 22: Alternative for Germany (AfD) delegates are escorted by riot police to the Alternative fuer Deutschland (AfD) party congress in Cologne, Germany on April 22, 2017. ( Leon Kuegeler - Anadolu Agency )
COLOGNE, GERMANY - APRIL 22: People hold a banner mocking AfD Party Co-leader Frauke Petry during a demonstration against the right-wing party Alternative for Germany (AfD) in Cologne, Germany on April 22, 2017. The AfD party holds their party congress on the 22 and 23 April in Cologne. ( Leon Kuegeler - Anadolu Agency )
COLOGNE, GERMANY - APRIL 22: People participate in a demonstration against the right-wing party Alternative for Germany (AfD) in Cologne, Germany on April 22, 2017. The AfD party holds their party congress on the 22 and 23 April in Cologne. ( Leon Kuegeler - Anadolu Agency )