Then how does SCOTUS "incorporate rights to the states" via the 14th?
The 14th amendment says (in part): "nor shall any State deprive any person of life, liberty, or property, without due process of law;
On a case by case basis, activist courts have said that some right (speech, press, privacy, whatever) is so fundamental to the concept of "liberty" in the 14th amendment that the states must also protect this right. It may not be denied any citizen without individual due process.