The difference here is that the politicians know that votes are fickle, but money is money.
I just thought of another problem with this though: for money to really speak, it has to at least have the appearance of being a continual stream. That means that once this $12mil warchest is used up, there has to be assurances that there will be ANOTHER war chest lined up to keep supporting things. Otherwise, it's easier to go with the other PAC who wants to keep things as they are, but will only donate $3mil/year.... for the next 20 years.
Lessig has to ensure this thing stays funded not just until the PAC's goals are realized, but until the goals of those being funded are realized. Otherwise, other deeper-running money may speak louder.