One of the usage rules drilled into my head many years ago is that due to can be used only as an adjectival phrase and that often the phrase we need is because of, which works as an adverbial phrase.
The classic example is:
I fell because of the ice on the sidewalk. (because of modifies the verb fell.
My fall was due to the ice on the sidewalk. (due to acts as a subject complement — an adjective to modify fall.)
I have relaxed my reflexive change of due to/because of constructions over the years because it seems to me that the distinction matters little to even good writers and editors and that the “error” won’t stop most discerning readers.
But I read a sentence in a published news story this morning that did stop me. And my abrupt halt was due to due to.
Here is the sentence:
Troopers investigating the death said they can’t say why Sutton’s license was suspended in South Carolina, due to privacy laws.
Does it sound as if the driver’s license was suspended because of privacy laws? On second thought, I understood that privacy laws affected the troopers’ release of information about why the driver’s license was suspended. The comma helps, I suppose, but I think that sentence needed editing. And as long as we’re fixing it we might as well correct the use of due to.
Here are a couple of suggestions:
Troopers investigating the death said that because of privacy laws they can’t say why Sutton’s license was suspended in South Carolina. (because of privacy laws tells why the troopers can’t talk)
Troopers investigating the death said privacy laws prevent them from saying why Sutton’s license was suspended in South Carolina. (This gets rid of the problem altogether.)
These webpages offer more insight on due to and because of.
Professor Malcolm Gibson’s Wonderful World of Editing
Daily Writing Tips (This explanation gives a good trick to use to discern the correct use of due to.)