Alexis Tsipras wound up his campaign to be re-elected Greek prime minister by declaring his victory would strike a blow for Europe’s left, as final polls on Friday gave him a slim lead. The return of his SYRIZA party to power after today’s vote would deliver “a key message for Europe,” Tsipras told thousands of supporters in Athens during his final electoral rally. “Do we want a Europe of austerity or one of solidarity and democracy? The result [of the vote] will be a key message for...