Larry Lessig proposes to lessen the influence of money on legislators. Unfortunately for him, he is trying to hide a symptom without curing the disease. The disease is that governments regulate businesses. The symptom is that businesses then have a profit motive in regulating governments. If you want a government which is free of corruption, you have to eliminate the motive for corrupting them.
The solution is a "Freedom of Trade" amendment to the Constitution. Word it like "Congress shall pass no law respecting the freedom of trade. Congress may tax trade without respect to its nature only on a percentage of price."
Update: it seems that Larry agrees with me, so it will be interesting to see what goes up on Change Congress. The only realistic solution that I see to excess power at the federal level is for the states to demand their power back. In order for that to happen, first the people must be changed, otherwise the states won't know to demand their power.