Reason magazine's Dave Weigel and Julian Sanchez have a must-read piece digging into the question of who wrote Ron Paul's newsletters. There's also some very interesting background on the history of libertarianism, and how Lew Rockwell and Murray Rothbard hoped to turn it into a neo-populist movement based upon racial resentment (thus the amity for Pat Buchanan and David Duke). It appears that the man in charge of the newsletters was indeed Rockwell, whom Paul can't renounce because he's his longtime guru.
An interesting fact that the dynamic duo dug up was this:
The publishing operation was lucrative. A tax document from June 1993—wrapping up the year in which the Political Report had published the "welfare checks" comment on the L.A. riots—reported an annual income of $940,000 for Ron Paul & Associates, listing four employees in Texas (Paul's family and Rockwell) and seven more employees around the country. If Paul didn't know who was writing his newsletters, he knew they were a crucial source of income and a successful tool for building his fundraising base for a political comeback.
So Ron Paul was pulling in nearly $1,000,000 annually from racist, homophobic, paranoid bile -- and he had no idea where the checks were coming from?