It makes no difference what you or I think. What matters is what your state classifies the Sport Trac as. Some states have separate classifications for SUV's while others rank it as a Light Truck since most of the original designs were based on truck chassis. Even some mini-vans are classified as Light Trucks and are not required to meet all the Federal safety standards and gas mileage standards required for conventional passenger cars. That was the whole reason behind why automakers started making mini-vans, SUV's and more luxurious pick up trucks was to side-step the safety and CAFE mileage standards that was imposed on regular passenger cars.
In Texas they can be classified either as Passenger vehicles (includes SUV's) or Pick-Trucks. They can even be registered a "Farm vehicle" which even has a cheaper registration.
In California, they registered some early Sport Trac's as SUV's but California claimed that if it had a pick-up bed, then it must be registered as a Pick-Up Truck. California charges quite a bit more for Pick-up truck registrations and taxes than they do for SUV's or other passenger vehicles. So it all depends upon how your state classifies it.
Liability insurance tends to be based on the size and weight of the vehicle since large vehicles will inflict more damage than smaller ones. Since the Sport Trac is based on the Explorer platform, it should be classified the same as anyother mid-sized SUV. Collision insurance is based on the value of the vehicle and the repair cost history of that vehicle, so it makes no difference if it's listed as an SUV or a Truck.
...Rich