The more that right-wing terrorists make death threats, berate Parkinson victims, call congress members racial and sexual slurs, spit on congressmen (John Lewis who'd been beaten nearly to death by Klansmen in 1961 and Selma police in 1965), shoot out the windows of representatives and cut the gas line to the home of a congress member's brother(someone could have died if they hadn't noticed the fumes in time)the more people in the center are going to recoil in revulsion from the anti-health reform forces, whether they liked the bill or not.
And prominent Republicans who refuse to strongly condemn this domestic terrorism now will be further tainted if, God forbid, another Oklahoma City type event occurs. Republicans were never perceived as being in any way involved with the militia movement back then, but this time around there is a real perception that the extreme rhetoric from conservatives in government (comparing the bill to the Holocaust, more damaging than 9/11, the death of freedom in America, etc.) is egging on the reptile-brained, knuckle dragging lunatic fringe of the radical right.