Voters in Hungary head to the polls on Sunday to determine the future of Prime Minister Viktor Orban. If the election results shift, it could mark the end of his 16-year rule as a prominent European leader.

In Hungary, voters head to the polls Sunday. At stake: the future for populist Prime Minister Viktor Orbán, Europe's longest-serving leader - and an ally of Presidents Donald Trump and Vladimir Putin. <p>In Hungary, voters head to the polls Sunday. At stake: the future for populist Prime Minister Viktor Orbán, Europe's longest-serving leader - and an ally of Presidents Donald Trump and Vladimir Putin.</p><img src="https://media.npr.org/include/images/tracking/npr-rss-pixel.png?story=nx-s1-577332...