it makes the murder of Dr. Tiller, a human being, a little more palatable for certain people. If people who refer to "Tiller the Baby Killer" are the same group of people who find "abortionist" as part of their personal lexicon, then perhaps he ought to be using a less pejorative term.

Pejorative: adj.

1. Tending to make or become worse.
2. Disparaging; belittling.

A disparaging or belittling word or expression.

For the (sizable, demographically speaking) population of people for whom "abortionist" is synonymous with "murderer" (actually, "child murderer), the term is disparaging. Because it is invariably employed as a disparaging term, it is also viewed as belittling (by intent) by people who don't find the terms synonymous. Saletan either knows this and chooses to ignore it, or he's used it strategically. For my money, that makes him dishonest or irresponsible, and suggests his defense is disingenuous. I'm disinclined to view intelligence as a factor.