To claim that these representatives don't make their decisions based on morality, or any other value that individuals have, is strictly false.
One might argue that only individuals who have opinions in line with national interests are electable, but that would be bullshit. If there's anything to truly be internalized about the elections of Barack Obama followed by Donald Trump, it's that individuals have a profound influence on American policy. If there were national interests that were solely responsible for US policy, they why was both foreign and domestic policy profoundly different across presidencies?
I'm genuinely curious how your worldview has an answer to this.