If a representative listens to what his constituents want and then uses his best judgment to decide how to vote, he is acting as a

trustee

Explanation:

According to my research on legal terminology, I can say that based on the information provided within the question he is acting as what is referred to as a trustee. Trustee's are defined as anyone in a position of trust and so can refer to any person who holds property, authority, or a position of trust or responsibility on behalf of the person placing the trust on the trustee.

I hope this answered your question. If you have any more questions feel free to ask away at .

all of them lol cause theres no map

answer; humanistic;