Mary Jane Stoneburg, one of our Good Word editors (along with Paul Ogden and Luciano Eduardo de Oliveira), has complained about the use of the objective case with than in several of our recent Good Words. Now Carolyn Whitaker has written in agreement with Mary Jane, so I have to respond more fully.
If you check the US and British dictionaries (including the OED) you will find that “than” is accepted as both a preposition and conjunction and, as a preposition, it requires the objective case. The OED says that it is only a conjunction but is used with the objective case of pronouns, an odd conclusion at odds with current English grammar.
The earliest citation of this usage appears to be 1560 in the Geneva Bible, Proverbs xxvii:3: “A fooles wrath is heauier then them bothe”. A few years later it appeared in Agrippa’s Of the vanitie and uncertaintie of artes and sciences, translated by James Sandford (1569:165): “We cannot resiste them that be stronger then vs.” So this usage has been around a long time.
Nor is it uncommon or unexpected. Prepositions come from a wide variety of sources: verbs (save, except), adjectives (near, nearest, like), adverbs (aboard, outside, out), participles (following, concerning), conjunctions (than, as, but—as in everyone but her), even the occasional prepositional phrase (alongside).
While many careful readers try to use than purely as a conjunction, the examples drawn from various sources over the centuries in the OED show that this change is not an example language degeneration. I see nothing wrong with going with the flow here, given the origins and histories of conjunctions.