It really has little to do with "liberal" and "conservative", or D vs R. It's really a class issue. The political elite and the self-proclaimed intellectuals don't want the Hoi polloi to have the any means of resistance. Even if they are not exploiting the underclasses, they reserve the right to do so.
I think that's another reason the constitution (Article I, Section 9) prohibits titles of nobility.
"The only way to stop a bad guy with a gun is with a good guy with a gun"