Guatemala's Bernardo Arevalo triumphed in Sunday's presidential runoff, but a bitter post-election battle is already underway, with adversaries maneuvering to kill his party and launch a wave of arrest warrants that could ultimately target him. The reform-minded son of an ex-president, who for many embodies democratic hopes in a country where dictators cast a long shadow, won by a landslide on the back of widespread support for his anti-corruption message. Preliminary results show Arevalo securing 58% of the vote, well ahead of the 37% for runner-up Sandra Torres, a former first la...