LITTLE ROCK, Ark. — When the leading Democratic presidential candidates marked Martin Luther King Jr. Day by linking arms and marching through South Carolina, Michael Bloomberg was nowhere near the early primary state. Instead he was in Arkansas, which votes March 3. The decision illustrates the parallel race Bloomberg is running to try to capture the Democratic nomination for president. He's bypassing the first four voting states to focus on the 14 states that vote on Super Tuesday. It's a nontraditional approach that has never been successful. But Bloomberg has already spent more than $200 million on ads, 10 times the leading candidates, and voters are noticing.