Columbia, United States (AFP) — Hillary Clinton has won South Carolina’s Democratic presidential primary by a wide margin, US networks projected, handing her a welcome victory over Bernie Sanders before the high-stakes “Super Tuesday” contest. “To South Carolina, to the volunteers at the heart of our campaign, to the supporters who power it: thank you,” Clinton tweeted as CNN, MSNBC and Fox News all called the vote in her favor at the close of polls on […]