"A modern day mass migration is taking place … that could change the face of Europe's civilization," warned Hungarian President Viktor Orban.

"If that happens, that is irreversible. … There is no way back from a multicultural Europe," said Orban. "If we make a mistake now, it will be forever."

Orban acted on his beliefs. He erected a 110-mile fence on the Serb border, redirecting hundreds of thousands of migrants away from Hungary to Croatia, thence to Austria and Germany.

Sunday, after a third of a million had passed through, Croatia replaced a center-left with a rightist party. A fortnight ago, the right-wing eurosceptic Law and Justice Party won a landslide victory in Poland.

Support for Angela Merkel, who has opened Germany to a million migrants, is plummeting. Bavaria's CSU, sister party of Merkel's CDU, is in rebellion. Bavaria has been the main port of entry for the hundreds of thousands of arriving migrants.