HODMEZOVASARHELY, Hungary—The election ads were both urgent and familiar: If residents didn’t vote for Hungarian Prime Minister Viktor Orban’s party, Europe would be swamped with migrants.
Pushed in billboards and Facebook ads, the campaign fell flat during local elections in this small town in the Hungarian heartland, once fiercely loyal to Mr. Orban, who built barbed-wire fences to keep out migrants at the height of Europe’s 2015 refugee crisis.
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