COLUMBIA — Republican support for former South Carolina Gov. Nikki Haley dwindled in her home state over the last few months while Donald Trump’s already commanding lead grew, according to the latest Winthrop Poll released Wednesday. The poll, conducted after Trump won the New Hampshire GOP primary, shows the former president with a whopping 36 percentage-point lead over Haley among those likely to vote in South Carolina’s Feb. 24 contest. Early voting started Monday. Haley’s overall support grew as she picked up voters who previously backed GOP contenders who dropped out. However, twice as ma…