I'd say the general consensus from TNR's Talkback is that this was a last minute smear timed for the New Hampshire primary. From TNR Talkback, #26, Sean posts:
From Ron Paul: January 8, 2008 5:28 am EST ARLINGTON, VIRGINIA - In response to an article published by The New Republic, Ron Paul issued the following statement: "The quotations in The New Republic article are not mine and do not represent what I believe or have ever believed. I have never uttered such words and denounce such small-minded thoughts. "In fact, I have always agreed with Martin Luther King, Jr. that we should only be concerned with the content of a person's character, not the color of their skin. As I stated on the floor of the U.S. House on April 20, 1999: 'I rise in great respect for the courage and high ideals of Rosa Parks who stood steadfastly for the rights of individuals against unjust laws and oppressive governmental policies.' "This story is old news and has been rehashed for over a decade. It's once again being resurrected for obvious political reasons on the day of the New Hampshire primary. "When I was out of Congress and practicing medicine full-time, a newsletter was published under my name that I did not edit. Several writers contributed to the product. For over a decade, I have publically taken moral responsibility for not paying closer attention to what went out under my name."
I agree with the noting that the Lew Rockwell/Mises Institute libertarians and the Cato/Reason Magazine libertarians are entirely different animals. Libertarianism and the confederacy make strange bedfellows.
Cedarstripper