Single-member district is the electoral district or constituency where single representative or officeholder is selected by voters.The official person usually consist of various members with him/her as legislative body.As there is single winner opted through votes, it is also called single-winner voting.
According to the question, John Garcia's office is present in single member district as he is the only representative in the elections and thus he can only win.
Lobbyists try to influence officials working in all three branches and in the federal bureaucracy. However, the influence is bigger in Legislative and executive power.
