You have no guarantees in mans law and no rights but from God. Where is your right to pursue happiness if it is your belief that it makes you happy to violate others. Indeed God wanted us to have governance on earth that reflects his goodness. That reflects his goodness is the key to it all. The major problem is that without laws that reflect his goodness there is no Freedom. No Justice, No American way.
The Libertarians do not support laws that reflect his goodness. They support laws geared towards self satisfaction and gratification wholly devoid of His Goodness. So if you do indeed support Aquinas' then there is no way you can support the Libertarians.
Have you been reading this thread?