Who does a US Senator represent?

All the citizens within his/her home state. The origins of Senatorial elections were that a Governor would elect the two Senators to represent the state of their election. The 17th amendment changed the election process to that of a popular public vote, but their duties were not changed. Unfortunately, as they are elected by the public, the States have little to no voice now to protect themselves from the ever growing Federal Government, which had been part of the reason for having Senators in the first place: to let the national issues, like defense or foreign relations, be decided by the Federal Government, and the rest by the states.and also all people in United States