S.C. voters will pick their choice for president, Congress and dozens of state legislative races in November. But how much will their votes matter? Not much, maybe. The contests in most S.C. legislative districts were over before qualifying for the races opened or were settled in June’s primary. On Nov. 8, voters in only 28 percent of S.C. legislative districts will have a choice of more than one candidate on the ballot. In half of the 170 State House races, incumbents will coast to reelection having faced no opposition.