Guys, this is so not playing fair. By all means, go ahead and encourage the faithful to vote consistently with Roman Catholic teachings on abortion. There are perfectly logical arguments available as to why Catholics should vote for pro-life politicians. For example, if one believes that humans are ensouled from conception, and that the ensouled have a God-given, inviolate right to life, it's easy to see how this right could outweigh any maternal interest in reproductive autonomy and could require not only abstaining personally from abortion, but also voting to proscribe other citizens' acts that are tantamount to murder. I reject the supernatural premise of this argument, and independently reject its conclusions, but it's certainly a fair argument to raise among believers.
What seems unfair to me is to threaten voters with catastrophic supernatural consequences for not towing the line. Threatening catastrophic Earthly consequences for political decisions is one thing--voters can presumably evaluate for themselves the chances that impeding the Bush administration will result in "the smoking gun . . . be[ing] a mushroom cloud." But to suggest that Jesus is peering around the curtain at your Diebold Accuvote TSX--and will cast you into the abyss if you touch "Giuliani"--crosses a certain line.
Because, really, how can any pro-choice argument hope to prevail in this version of Pascal's wager? As long as one believes there is any non-zero probability of eternal punishment for voting pro-choice, the disutility of such a vote registers at infinity. The utility of a pro-choice vote--in support of rights exercisable only during the finite human lifespan--is necessarily lower.
To be fair, the Bishops also encouraged voting against evils such as racism, and there is a lot to like in the Church's social policy positions on poverty. I do consider it my ethical duty to vote for poverty relief and against racism. But I'll thank you, Conference of Bishops, to let me get there without supernatural threats of eternal torment.