While South Carolina  would never be called a gay-friendly state, don’t believe everything you hear. Charleston  and Columbia , in particular, are quite accepting of homosexuals, and gay and lesbian travelers shouldn’t expect anything untoward to happen. Because of its general religious conservatism, the Upstate could be considered the least gay-friendly portion of the state.
In small towns all over South Carolina, the best approach is to simply observe dominant Southern mores for anyone here, gay or straight. In a nutshell, that means keep public displays of affection and politics to a minimum. Southerners in general have a low opinion of anyone who flagrantly espouses a viewpoint too obviously or loudly.