Conservatives. They tend to think largely in terms of absolutes. Now don't get me wrong, absolute values are important - by no means do I support moral relativism - but it's necessary to recognize the many shades of grey involved in individual cases too. That is, after all, what situational ethics is all about.
I suspect that many of the conservatives I've met don't recognize these gray areas largely because of their absolutist religious upbringing.
A few scenarios:
A nine year old girl, tragically, is raped and impregnated by her stepfather. What to do? According to the religious absolutist, abortion is, under all circumstances, 100% wrong. Unless the birth is life-threatening, she can't abort.
Moderate: I don't normally support abortion, but here it's necessary.
Liberal: I think abortion is a right that belongs to the mother. I would support her right to choose if this girl was nine or twenty nine, raped or non-raped. (although i would personally disapprove of it in the latter).
Conservative: Fucking baby killers! It's an innocent fucking BABY we're talking about!
(as opposed to a non-sentient cluster of cells, lacking a nervous system and the ability to feel pain)
I had a much better example but the stupid character limit fucked me over.
See my future definition, Conservative Black and White Thinking Disorder
for that one.
I blame religion for turning so many conservatives into black and white thinkers.
And this is why I dislike religion - it so often stops people from thinking. If people were encouraged to think in terms of individual cases as opposed to coming to each and every unique situation with a preconceived bias (abortion is MURDER!)...well, I don't know. We might have a better world. Just maybe.