(a) We have a system for resolving political disputes in this country. We elect people, and those people make laws. When those laws are within the limits set by the Constitution, they are binding. When not, a court can strike them down. When we want to, we can change the Constitution, though it is (rightly) rather difficult.(b) One inconvenient thing about democracies is that it is very, very unlikely that your own side will prevail all the time. You get a voice, but so does everyone else, and barring stupendous coincidences, this means that things won't always turn out the way you think they should.(c) It would be naive to think that you will lose only on unimportant questions. Governments make hugely consequential decisions all the time. Sometimes, these decisions lead to the killing of innocent people, in ways that you think are deeply wrong.(d) If anyone who believes the government had adopted a policy that would lead to the killing of innocent people is justified in killing people to stop this, then we might as well just decide not to have a government at all. During the Bush administration, half the country would have been justified in trying to assassinate the President and members of his administration. Any corporate executive who works for a company that does not adequately protect its workforce from poisoning or injury would have to watch her back. Etc., etc., etc.
(e) If you are committed to our form of government, you must leave some room between (1) the claim that some policy it adopts is wrong, even very wrong, and (2) the claim that you can kill people to prevent this wrong thing from happening.
Sure. As an empirical matter, I believe that national health care is going to kill a lot more people every year than the Iraq War when fully realized. Am I justified in shooting someone? No, both because the moral intuition attached to affirmative acts like abortion is different from the moral intuition attached to a sin of omission, like changing the health care system in such a way that its production of new life-saving drugs and techniques falls dramatically.
But more importantly, because it's the outcome of a legitimate political process in which I am a willing participant.
My argument is that abortion, like slavery, is becoming in this country an issue upon which people have no reasonable political recourse. I'll go further, and say that the process by which 7 judges enforced their consciences on the American public was itself borderline illegitimate; it was first, not in their proper job description, and second, a bad way to run a government.
Yes, in theory pro-lifers could pass an amendment. And in theory, the Palestinians have access to the political process too, as right wing blogs often point out--all they need to do is elect a coherent government that Israel is willing to negotiate with. Most Obsidian Wings posters and commenters don't have much trouble discerning that a sufficiently remote possibility of political access is not political access, and that the individual Israeli actions which might be justified in a democratic government acting on an enfranchised population, are problematic when Israel does them to the Palestinians. After all, we bulldoze peoples' homes, too--we just call it eminent domain.
Questions of fundamental human rights that have been closed off from the normal political process are very likely to produce violence. I can simultaneously, as I do, want Tiller's murderer given a long jail substance, and worry that we've left his fellow lone gunmen no other outlets for their legitimate moral beliefs.
Is it naive to think that the political process would tame this rage? I don't think so. The political process would always offer some marginal victory worth fighting for, whereas now, any marginal victory is more likely than not to be struck down by a court. But also, federalism would mean that most people would live in systems they found largely agreeable, assortative relocation being what it now is in America. And peoples' outrage is very much shaped by their local environment--notice that pro-lifers don't travel to Sweden to protest, or kill abortion doctors.
But, of course, that means tolerating more restrictions on abortion than we now have, some of them stupid restrictions, as government laws will be sometimes. If you are as convinced as the pro-life fringe of your moral position, then this is intolerable--far better to talk about sending armored brigades to escort abortion doctors to their work.