AACHEN, Germany—Political hopeful Bernd Lucke has a simple explanation for why his fellow Germans have so far agreed to pay billions of euros to keep Greece and other Southern European countries in the euro zone.

"Eighty percent, if not 90%, of the people have no knowledge of economics whatsoever," said Mr. Lucke, a professor of economics and head of upstart political party Alternative for Germany. "The situation is very dangerous for Germany and the European Union."

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