How did Russo win? Only in Bridgeport has the town-by-town breakdown:
Overall in Trumbull Russo won 2236 to 893.
In Monroe it was Russo 522 to 204.
In Bridgeport, despite an overwhelming voter registration advantage, Mulligan managed to take the city, unofficially, by just 1094 to 833. Russo won Winthrop School in the North End and Hooker School on the Upper East Side.
Which means the map looks something like this: