Years of fighting losing battles have left the NCAA almost helpless to defend itself.The legal pile-on against the largest governing body for college sports in the Unites States continued Wednesday when attorneys general from Tennessee and Virginia filed an antitrust lawsuit that seeks to throw out the few rules the NCAA has to regulate how athletes can be compensated for name, image and likeness.That pushes the number of antitrust lawsuits the NCAA is actively defending to at least five.Denial and previous court losses …