Ron Paul, though a Republican in Congress, has often been seen as a libertarian through his votes. He has what some would say in an antiquated take on foreign policy, often voting against any type of proposal that was put forth that would support a war or military action and generally supporting non-intervention. His fiscal stewardship has led him, several times, to be one of only a few "No" votes, often voting against giving Congressional Medals of Honor. He'd follow up by asking every member of the House of Representatives to pledge $100 of their own money to pay for the cost of the medal. He's also pledged not to take a congressional pension.
However, despite many of these policies that I support or at least respect, I don't think he's ever been put under the microscope. He often gets just enough attention to be a Media Darling for a while, and that's about it. I've never heard a really good explanation for these racist newsletterssent out under his name, or some connections to white supremacy groups, and I think his views on the Civil Rights Act are flat out wrong. And during his 24 years in Congress, he's voted several times to build border fences and increase patrols, but has never tried to fix our broken system of legal immigration.
Personally, I much more prefer the libertarian leanings of former Governor Gary Johnson (also running for President) than Ron Paul. He has a lot of the same beliefs, but with executive experience to back it up without some of the questionable connections Paul has.
I wish Dr. Paul well in retirement, but I can't quite say I'll miss him too much in the United States Congress.