They care a little about votes, since they need occasional public office on their lobbyist résumé, and as a source of networking. Being in public office at least some of the time tells those who hire lobbyists that you have both the bullshitting skills needed to convince people, and have connections in the old buys club of congress. So you need to get votes some of the time. But some of the time doesn't have to be a whole lot. If you only get into office after the voters have become so sick of Republicans that they would vote for a turnip, that's fine. The only other thing that matters is how much of a team-player you are, which is to say how well you represented your donors while in office, rather than the people.