Many people are deeply insecure about the difference between who and whom, resulting in hypercorrect insertions of whom where it doesn't belong. So it's interesting to find a writer using whom in the correct case while simultaneously falling into a different error, one that my intuition tells me should be much easier for native speakers to spot. The following paragraph comes from an Onion article with the title Wal-Mart Cuts Over 13,000 of What it Calls Jobs. The running joke of the piece is that wherever the words workers, jobs, or similar terms are used, denigrating qualifiers are inserted:

"Clearly, this move signals what I'm coldly and unemotionally going to describe as a change in Wal-Mart's current business strategy, and statistics show that it may pay off for them in the long run," economist and author Jeffrey Fields said. "And as for the poor, exploited creatures whom I shall skirt the issue and refer to simply as workers, I'm sure they will be back on their feet in what no honest observer of the facts could possibly describe as no time."

The case of whom is impeccable here, as it's the object of the preposition to (cf., "refer to them), and yet the sentence is still deeply flawed. The problem stems from a violation of the "coordinate structure constraint," one a of a number of restrictions that are often called island constraints. In brief, this is a restriction on what parts of the sentence can be turned into a relative pronoun. Think of a sentence (or clause) with a wh-word as containing a gap. For example:

I had dinner that night with the woman whom I saw ___ swimming in the morning.

The gap indicated above (___) shows the place where the phrase "the woman" would appear if the relative clause were an ordinary declarative sentence ("I saw the woman swimming in the morning."). Many versions of syntactic theory call this pattern wh-movement, because the wh-word is seen as moving from the site of the gap to its final position. The coordinate structure constraint says that this movement is ungrammatical when the gap is inside a coordination (and, or, etc.) unless there is a gap inside each coordinated element. For example,

*The woman whom he saw and ran away later became his wife. (cf, "He saw her and ran away.")

In this example, there is a gap in the first coordinated element (he saw ___), but not in the second (he ran away). If we rewrite the sentence so there are two gaps, however, it becomes grammatical:

The woman whom he saw ___ and ran away from ___ later became his wife.

The same problem occurs in the Onion sentence, although the gapless coordinate in this case is the first half. The coordinator and links two predicates, "skirt the issue" (no gap) and "refer to ___ simply as workers." Since there's no obvious way to rewrite "skirt the issue" to contain a pronoun referring to the workers, fixing this sentence requires bigger changes than did my manufactured example. We could, for example, simply delete the first coordination:

And as for the poor, exploited creatures whom I shall refer to simply as workers...

Or we could keep the substance of the qualification by changing it to an adjunct:

And as for the poor, exploited creatures whom I shall, skirting the issue, refer to simply as workers...

Usage books don't, as far as I know, discuss the coordinate structure constraint. That's because sentences like this are fairly obviously wrong on an intuitive level, and so little comment is required. Could it be that the writer of the article was so focused on the case of whom that he or she lost sight of the more fundamental grammatical flaw?