People who are good at lobbying are basically the same type of people who are good in politics and other fields where it is important to use your charm and knowledge in a social way in order to influence people. You'll need to be smart but smart in communicating to others too.
You will need to be persuasive because you'll be trying to talk someone into believing something or going with the cause at hand. You will need to like people and...people will need to like you. If you have a great vibe and good energy about you, that is a big plus as well. The same type of person who people like to listen to and be around are the ones that make the best lobbyists ever.