By Ross Dellenger The ACC commissioner believes his league can still close the gap with the SEC and Big Ten. CHARLOTTE — Jim Phillips is holding on to the string, gripping it as tightly as ever as the balloon drifts toward the heavens. The college athletics model we have all known and loved for years is changing. It’s dying or, some might say, it is dead. It is floating like that balloon, off and away, never to be seen again. “If we take the path that it’s only going to be about football and basketball, shame on us,” Phillips, the ACC commissioner, said before hundreds of reporters at his leag…