USC is now considered a FB school...but for many years in it's past was considered a BB school. They used to be in the ACC for crying out loud, lol. USC's BB history is probably more down than up, but it's far more glowing than it's FB history. Their good years were few and far between - especially since the 70s - but when they were good they were VERY good. And their fanbase loves college basketball: there just hasn't been much quality to watch in recent years. When Mcguire had USC winning in the ACC, the crowds were among the most passionate in the south. When Fogler had USC competitive in the SEC, the fan support helped pave the way for the building of Colonial Life Arena. The 1st 2 years under Horn, USC was selling out CLA for most SEC home games.
The fanbase for USC BB is real mercurial: if the program is losing, they leave in droves...but if it's winning, they return in droves too. USC has had problems with recent coaching staffs in that they have struggled finding the right combination of good coaching with good recruiting. Fogler at first hit all the buttons bringing in several McD AAs, but it faltered in the end. Odom was a solid teacher of BB, but his staff recruited poorly.
South Carolina is nestled in between NC and GA, with FL just down the road. They are definitely immersed in college basketball territory...if they can hire some aggressive young recruiters on their staff, there's enough quality talent in the areas even with UNC, Duke, NCSU, GT, UGA, and the FL schools for them to field competitive teams. As long as they start winning, the fans will pour back into the CLA and support them.