The best dirty trick I ever heard of was related in one of my high school classes. When the time came to choose a county seat for Tarrant County, Texas, a special election was held in which residents went to the town they preferred to cast a vote. The race was between Grapevine and Ft Worth. Grapevine was expected to win so the city fathers bought a large keg of whiskey to give each voter a drink from. Ft Worth won by the simple expedient of stealing the keg, advertising the fact, and guarding the keg better than it's original owners had.