If you don't have time to read the article I've linked to, I'm providing the summary from the artcle here:
Ron Paul: More Robertson than Goldwater
While Paul talks the talk at times for libertarianism and pro-liberty, I don’t think he walks the walk. He is on the side of liberty on many issues and should be praised for that.
However, when it comes to many of the most important issues, including many issues most influenced by a president — such as immigration and trade — he is usually on the side of anti-liberty forces.
On social and culture issues, such as religious freedom, homosexuality, and reproductive rights, he is a traditional religious conservative and sounds nothing like a libertarian.
Most worrisome, Paul advocates dangerous and irresponsible foreign policy views.
When he claims he only supports legislation expressly authorized by the Constitution, Paul is at worse a hypocrite and at best inconsistent and superficial. Legislation that he has sponsored and touted on his own web site belies this view.
He does not speak out, on his web site, against clearly un-constitutional proposals, such as nationalizing health care. Nor does he speak out against already established, yet not constitutionally authorized, programs and agencies such as the FDA, Medicare, and Social Security.
I do not see a principled defense or advocacy of liberty here. I see a man using the ideas of liberty to protect his view of America as a white, Christian country. That is not good for liberty, libertarianism, or America.