Democrats ran Joe Lieberman for VP. Raved about him. Four years later, they chased him out of the party. Too conservative.
Republicans have chased out a few RINOs, but several do remain. McCain, for one.
The parties have distanced themselves from one another to provide some sort of distinction. The saying goes, why vote for a conservative democrat when you can vote for a real republican.
They're both owned by special interests, but nobody is surprised by who those interests are. The voter can take that into account and vote accordingly.
Unfortunately, both parties are wrong on about half the issues. Otherwise Gore would have won huge without resorting to releasing W's DUI a couple days before the election. Or this election wouldnt be close (ObamaFatigue, Clinton fatigue).
Republicans do have the edge on pocketbook issues, or this wonderful summer of recovery v6.0 would assure a democratic landslide.
The electorate does seem to be engaged way earlier than in prior elections.
Are we divided? General public? Not that much, but many are too stupid to consider voting for the conservative democrat or the liberal republican because of the letter D/R next to their name.