LEWISTON — Shane Bouchard won the runoff to be the next mayor of Lewiston. In a dramatic turnaround from November, Bouchard overcame his progressive opponent, Ben Chin, who had come out on top last month. The unofficial tally gave Bouchard a 145-vote victory, receiving 3,663 votes to 3,518 for Chin. The winner will replace longtime Mayor Bob Macdonald, who was term-limited after three consecutive two-year terms.