And, it will backfire, among those undecideds who see the Church as opportunistic anyway. (If anything, the sexual abuse scandal proved that the bishops only acted when forced to act.)
If the bishops are just now acting against pro-choice politicians, when they've had 31 years to do so, they look political.
You are so lacking in logic. First you claim it has already been done and backfired, and then you claim that it would be the first time in 31 years (BTW, when was the last time a major party nominated a pro-murder Catholic for President?). BTW, what backlash happened when Grey Davis was told to STAY AWAY by the Bishop in Sacramento? That 'backlash' propelled Arnold into office, no? And what did the Bishop who told Daschle to stop calling himself Catholic get? What 'backlash' was there then? And what of the other coreageous hierarchs (all three of them, I think) who have told Kerry to STAY AWAY?