What is the best summary of this quotation?
“Congress has a split personality. On the one hand, it is a lawmaking institution and makes policy for the entire nation. In this capacity, all the members are expected to set aside their personal ambitions and perhaps even the concerns of their constituencies. Yet Congress is also a representative assembly, made up of 535 elected officials who serve as links between their constituents and the National Government. The dual roles of making laws and responding to constituents’ demands forces members to balance national concerns against the specific interests of their States or districts."
—James M. Burns, et al., Government by the People