Here's just one among possibly thousands of examples. If Archer Daniels Midland (ADM) used goons and violence to stop people from buying sugar from Caribbean producers so that sugar prices would rise, making it easier for ADM to sell more of its corn syrup sweetener, they'd wind up in jail. If they line the coffers of congressmen, they can buy the same result without risking imprisonment. Congress simply does the dirty work for them by enacting sugar import quotas and tariffs. The two most powerful committees of Congress are the House Ways and Means and the Senate Finance committees. These committees are in charge of granting tax favors. Their members are besieged with campaign contributions. Why? A tweak here and a tweak there in the tax code can mean millions of dollars.
You ask what can be done? Campaign finance and lobby reform will only change the method of influence-peddling. If Congress did only what's specifically enumerated in our Constitution, influence-peddling would be a non-issue simply because the Constitution contains no authority for Congress to grant favors and special privileges. Nearly two decades ago, during dinner with the late Nobel Laureate Friedrich Hayek, I asked him if he had the power to write one law that would get government out of our lives, what would that law be? Professor Hayek replied he'd write a law that read: Whatever Congress does for one American it must do for all Americans. He elaborated: If Congress makes payments to one American for not raising pigs, every American not raising pigs should also receive payments. Obviously, were there to be such a law, there would be reduced capacity for privilege-granting by Congress and less influence-peddling.