A clarification
Reader,
I believe that I made my point clear in my first response, but I will clarify. There are two metrics by which I would define extremism. One is on the objective merits of the position itself, the other is subjectively based on the proportion of the population that holds to a certain position.
The latter is more quantifiable, but more subjective. You would have been an “extremist” in the 1850s United States if you supported the complete abolition of slavery. Even still, your position would be morally justifiable, and in my opinion, the correct position. In general, it is helpful to look to surveys of the population to determine what positions are widely held and which positions are found only at the extremes. This does not imply a moral judgemnt of the position, but is only a statement of opinion. Yet by this standard, feminists who support and defend late-term abortion are at the extreme.
The objective moral quality of a position, however, should be valued as a more serious measure of extremism. This weighing mechanism cares nothing for who holds a position; it is concerned only with the inherent moral rightness or wrongness of the position. In this way, an entire population can hold a particular view, and it could still be honestly described as extreme. The issue of abortion in general, but late-term abortion in particular, fits squarely into the category of morally extreme, based on how I view morality.
Thus, while the charge of “extremist” carries a significant weight, I believe it’s use is fully justified in this case.