The implicit assumption is that you shouldn't have the legislator's ear because you have a fat check in hand. Chance are that the check will win over a petition.

If we are to have freedom of speech, then Beck should be able to have his show. That's the easy part.

Beck converts money into public opinion. Arguably, SuperPACs do the same. Hence the Citizens United decision. In practice, SuperPAC donors just tell the legislator why the check was written, or in which case it will be. Nothing wrong with the premise (free speech), plenty wrong with the outcome (money = voice, or rather money = ear?)

Now that I ran this circle, I can see how publicly financed campaigns might be the only answer. Thank you for asking a difficult question to answer. I'll definitely think about this more.