It's really fun to watch the Other Side experience the sleazeball sophistry of the Coulter Method, if only momentarily. This in particular jumped out:
One Web site defending Bush's choice of a graduate from an undistinguished law school complains that Miers' critics "are playing the Democrats' game," claiming that the "GOP is not the party which idolizes Ivy League acceptability as the criterion of intellectual and mental fitness." (In the sort of error that results from trying to sound "Ivy League" rather than being clear, that sentence uses the grammatically incorrect "which" instead of "that." Web sites defending the academically mediocre would be a lot more convincing without all the grammatical errors.)(Isn't that just so Ann? One putative grammatical error becomes "all the grammatical errors".... There's got to be a name for this greasy technique; I'd like to propose Coulterian Multiplication.)
At any rate, Ann's trying to score some cheap points here by schoolmarmishly twitting an unidentified Web site for a grammatical solecism. (Interestingly -- and oh, so Coulterianly -- she doesn't tell us which Web site it is; nor does she provide a hyperlink so we can verify her assertion that such a sentence even exists -- for all we know, she made the damned thing up.)
"Which" versus "that" is a rule of thumb, not a hard-and-fast law of grammar. I've seen many, many well-established authors (chiefly, but not exclusively, British) of enormous literary repute who exclusively employ "which" to offset restrictive clauses. I'm a former copy editor; this is the sort of thing that jumps out at you.
The particular use of "which" not "that" that Ann so confidently decries ("The GOP is not the party which idolizes Ivy League acceptability...") isn't actually incorrect at all. The phrase means exactly the same with either word employed. Go ahead; try it. "That" is preferred by many US styleguides in that case, but that doesn't mean that not using it is a violation of some kind of Immutable Olympian Law of Grammar, to be invoked by finger-wagging sleazeball wingnut columnists trying to make you look stupid.
There are times when offsetting a restrictive clause with "which" is truly incorrect. The sentence,
All the patrol boats in the Navy which are sinking should be scrapped.is worlds away in meaning from
All the patrol boats in the Navy that are sinking should be scrapped.But that doesn't apply to the usage that Ann castigates.
The sentence under discussion is, it must be admitted, monumentally crappy: the phrase "which idolizes Ivy League acceptability as the criterion" is about as pompously clumsy a thing as I've read all month, but criticism of style isn't Ann's strong suit. She'd rather serve up a cheeseball dinger that she thinks nobody's going to call her on. Sorry -- on which nobody's going to call her.
Well, I just did.