Poblic Citizen has an excellent reputation. Their studies are cited often in the news, and their lobbying is taken seriously in Congress. I am sure they have their bias, but they are not an organ of the Democratic Party. There are also a number of Libertarian websites that voice the exact same concerns:

http://www.lewrockwell.com/reese/reese103.html

http://www.ballotpaper.org/archives/000354.html