To most who knew Bruce Thompson, he was more than a conservative Republican who served in the Georgia Senate before he was elected two years ago as the statewide labor commissioner.

Oysters were a source of sustenance for centuries before the Georgia colony’s founding. A century ago, when canned oysters were a staple, the state’s annual oyster crop topped 8 million pounds a year.

This community nestled in the North Georgia mountains faces a prospect partly of its own making: It overwhelmingly backed ...