A November referendum to raise Mecklenburg County’s sales tax a quarter of a cent has yet to get support from a big booster: the Charlotte Chamber. The Chamber says it’s not against the purpose of the increase: using the generated money to pay for raises for CMS employees and to help prop up the area’s struggling arts and science centers. Rather, it says more discussion is needed on finding specific funding options. So, the Chamber is staying out of the referendum debate. Mecklenburg County Commissioner Dumont Clarke, a referendum supporter, says a Chamber-funded campaign would have helped pass the sales tax hike, but he remains confident.