Part of the reason Americans consider liberal an epithet [...] is because they mostly hear it used as an epithet.
When Obama disavows the term, he perpetuates that dynamic and allows conservatives like O’Reilly to continue tarring Democrats with a label most Americans consider negative, even if they’re no longer entirely sure why. It might be wiser, at least in the long-term, to explain why the specific policies many Americans support are liberal. And thus begin to reclaim the term.--Peter Beinart, The Atlantic, 2/5/2014
Please read the rest of the article "'Liberal' Is Good" on theatlantic.com. I couldn't have said it better myself.