This American Life has an in-depth episode up on money in politics from last week provides a window into this commonly misunderstood part of politics. Listen here. This is a quote from Sen. Russ Feingold in the latter part of the program during his interview with Sen. John McCain.
"...Well, it's never been this way, since 1907. It's never been the case that when you buy toothpaste or detergent or a gallon of gas, that the next day that money can be used on a candidate that you don't believe in. That's brand new. That's never happened since the Tillman act and the Taft Hartley Act. And so, people have to realize this is a whole new deal. It's not business as usual..."
Related, The New York Times reported yesterday that the FCC " is moving forward with a plan to make local television stations post information about political advertising on a central Web site." Click through the MCH blog archive and you'll see more background on this issue.