India, April 7 -- Hungary's elections on April 12 will have profound aftershocks as many in the European Union hope for the defeat of nationalist Prime Minister Viktor Orban, who is widely seen as endangering the future of the 27-nation bloc.

Orban, the EU's longest-serving leader, has trailed in the polls. His 16-year grip on power has tested the EU system of governance meant to ensure peace through economic and political integration after the ravages of the world wars. His rival, Peter Magyar, told the Associated Press he would repair Hungary's relationship with the EU if elected. The EU is grappling with enormous threats: the rise of right-wing populism, conflicts in Ukraine and the Middle East, Russian sabotage efforts, Chinese econo...