Democrats and Country, for sure, though there are segments of both parties that are okay with either (Trust Fund College Republicans generally LOVE rap, NPR Liberals probably like strains of old school country, and whatever's left of southern Democrats obviously love country). If we are going to be that simplistic about it, that is.
What interesting about many liberals is how much they despised rap music, despite being rooted in black culture. Look at sites such as Daily Kos and Democratic Underground, you'll see endlessly complaints about the genre, often misguided and borderline racist. Now you see Republicans such as Marco Rubio enjoying the rap genre, while I bet many Democratic members can't stand listening to the music, often due to political incorrectness. I bet there might be a shift among white people in the future regarding this dichotomy.
That's what really pisses me off about the politically correct crowd - they just don't get the bigger picture. When rap is politically incorrect, it reflects a hard reality. The truth is, sometimes offensive language is necessary to reveal truth.