From The Fallacy of Campaign Finance Reform by John Samples
accessed at http://www.press.uchicago.edu/Misc/Chicago/734501.html
In recent history, Republicans have generally raised more money than have Democrats. Republicans have also relied more heavily on money to fight elections. In contrast, Democrats can count on unpaid labor provided by members of their coalition and favorable free coverage by a largely sympathetic national media.
Neither volunteers nor the media have been seriously regulated by campaign finance laws.
By reducing a Republican advantage while ignoring a Democratic strength, campaign finance law has generally biased elections toward the Democrats.
As we shall see, the 1974 Federal Election Campaign Act—the foundation of campaign finance regulation—responded to certain threats to the Democratic majority that then controlled Congress.