If you're going to criticize the harsh, escalating, polarizing, and purportedly violent partisan rhetoric of the Evil Other Party, then you have a duty to not engage in harsh, escalating, polarizing, or reasonably-perceived-as-violent partisan rhetoric yourself.
Policy disagreements are just that. Begin from the assumption that the other side is not threatening to turn America into a tyrannical totalitarian state, they're just plain old wrong. Then explain why their ideas are wrong and why your ideas are better.
Neither strident Republican rhetoric nor strident Democratic rhetoric caused Jared Lee Loughner to open fire in Tuscon on Saturday. Jared Lee Loughner was mentally ill and lacked the capacity to form any kind of a coherent or even identifiable political ideology. No one gets to pin him on the other side.
If you think the Other Guys are guilty of promulgating immoderate, dangerous rhetoric, then take care that your rhetoric is calm and reasonable. And don't consume intellectual product from those who engage in immoderate, dangerous rhetoric regardless of their ideology. Don't change your mind -- but do debate responsibly.
That is all.