I think the big problem is not that there is too much partisanship, but rather, not enough.
If we had more than two dominant political parties we would be much better off. If the typical Democratic candidate stands for the typical party line, then who do you vote for if you are anti-war, pro-nanny state, anti-abortion, pro-gay rights? If the typical Republican candidate stands for the typical party line, then who do you vote for if you are a warmonger, low tax, pro-abortion, anti-gay rights?
Take me for example, I am...
a pacifist (I don't expect anyone else to live by my morals though)
against capital punishment (goes with the whole pacifist thing)
anti-abortion (again, goes with the pacifist thing. don't think this is a rights issue, or rather, I think it involves the rights of more than one person)
pro-(insert any group here) rights (I hate institutionalized discrimination. however, I respect your right as a private citizen to discriminate, even if I think that makes you evil. I won't try and force my morals on you)
pro-business (without a healthy business atmosphere, we don't have a healthy economy and then we are all up a creek)
anti-tax (if you want something, earn it, don't take it from others)
anti-illegal immigration (I think they should open the borders and let people come and go as they please, then there is no such thing as illegal immigration)
anti-drug war (it's MY body, you do what you want with yours. I personally find most drug use to be immoral, but I won't try and force you to live by my morals.)
anti-morality legislation (you can't legislate morality. period.)
those are some of my stances.
So tell me, how should I vote? More parties will mean more partisanship, but will also mean more choices and representation that more accurate reflects that will of the people.