Yes, I agree that a two party system is shit, but as of now I agree with the majority of the democrats opinions on social, foreign (except drone strikes), and economic policies. Thats why I identify as a democrat, if there was a party that more thouroghly held my beliefs, then I would side with them. However, if you vote for the GOP you are voting for what they believe in, regardless of whether you do. If you voted for Mitt Romney, then you voted against gay marriage, and for stricter immigration laws.
I don't know any liberal (and I live in portland, I know a lot of liberals) that thinks the United States should become a christian nation. Also, you know the super bigoted 1% "Southerner Republican" you mentioned? People like him comprise the tea party, which has been pulling the republicans to the right since its inception. I don't think that anybody says that all republicans have the extremist viewpoint, but the party as a whole does, because they need to pander to the far right to get both.
On another note, In my opinion, In about twenty or so years, the republican party will have all but disappeared, the democrats will move more to the center of the spectrum, and another party like the green party, will take over the liberal spot from the democrats.