I think we need to look at abortion not as a crime but as an ethical issue. That should take some of the heat out of the debate while still keeping us from turning our backs on it. I also strongly believe we should take religion out of the debate and rely on reason and empathy alone. I think reason and empathy form the necessary and sufficient foundation for a moral worldview. Religion only muddies the waters. As Arthur C Clarke said,
The greatest tragedy in mankind's entire history may be the hijacking of morality by religion.
It's a little like the vegetarian debate, which again should be divorced from religion. There are people who are strict vegans and do not favour any kind of human imposition on the animal kingdom, the "ordinary" vegetarians (lacto-vegetarians), the ovo-lacto-vegetarians who will not eat fertilised eggs (and those who will), people who will eat fish and poultry but not red meat, people who will eat "regular" meat but not dogs, cats, horses and monkeys, those who will eat anything that moves except humans, and of course, cannibals. To each group of people, those further "ahead" of them seem weird and/or immoral, and those "behind" them are unnecessarily squeamish and should get with the program.
It's a bit like the saying about driving - anyone driving slower than you is an idiot; anyone driving faster than you is a maniac.
The resolution to all of these issues is the recognition that there is no single line that divides the acceptable from the unacceptable. Real life is messy, and different people (however rational and intelligent) will fail to agree on where to draw the line. Each will draw it in a slightly different place, and we must learn to accept some degree of difference in our approaches to ethical issues without condemning people as either immoral or superstitious.
"So, after the non-controversial arguments against believing in imaginary friends, we have now moved on to the more controversial topic of human morality. As rational people, how can we be expected to accept someone else's line on morality without thinking for ourselves?