Originally Posted by NorfolkSouthern

If you ever tried to take an FAA medical examination, and got denied a medical certificate, then your driver's license would be ineligible, and for that reason, it would be illegal for you to fly a light-sport aircraft. Either a driver's license, or third class medical is needed. If a third class medical was denied, suspended, or revoked, then you would not be able to use your driver's license as a medical certificate. But if you have never taken the physical, then your driver's license would work ONLY in that case, and ONLY for light-sport.