Don't lobby. go to your local caucus and change it from within. Note that I said Caucus: even in a primary state there is some form of caucus where the party decides things. You want to be in this system, this is where the party platform is decided on. This is where the people who are working behind the scene to elect someone make the plans. In turn this is where politicians go to find people who will work for them. Which in turn means this is where you can have a one-on-one meeting from the standpoint of someone important to listen to. (when you spend a few Saturdays knocking on potential voters doors for someone that someone listens to you)
If both parties get anti-DRM legislation into the platform in random places you can be assured they will listen. If both parties see their big supporters as against something they will listen. Politicians do not want money, contrary to what you might think: they want a power, and in this country that means they need votes. Money (for ads) is one way to get votes, but real humans doing real work is at least as powerful.