WASHINGTON ― President-elect Donald Trump, who has pledged to build a wall along the United States’ southern border, won the presidential election on the 27th anniversary of the fall of the notorious wall that separated two halves of Berlin.

Observers are noting the irony of the date for a man who seems to have built his platform on dividing citizens, by promising to ban Muslims from entering the U.S., speaking of Mexicans as “rapists” and celebrating racist stop-and-frisk policies.

For Europeans, the coincidence is especially dark. They are particularly shocked by Trump’s wall proposal ― though it is hardly a new idea in American political discourse and border fencing (useful or not) has long had bipartisan support in the U.S., this seems like an unwarranted, hateful escalation

Many in Europe had seen the collapse of the Berlin Wall as a sign that divisions separating people and restricting their freedoms could not stand. Trump’s success challenges that cheery notion. It shows the continuing appeal of the kind of authoritarianism that marked the regime that built the wall to trap its citizens, Soviet-backed East Germany.

The businessman’s triumph also dovetails with two other inauspicious dates in European minds: The evening of the Kristallnacht in 1938, which ushered in the most horrific of Nazi violence toward Jewish people; and 9/11, because Europeans write dates with the day first and then the month.

German Chancellor Angela Merkel, who grew up on the oppressive East German side of the wall, congratulated Trump Wednesday morning. She pointedly noted that unified Germany and the U.S. share fundamental democratic principles; she said those would be the basis of her relationship with Trump, who has bashed her acceptance of refugees.