Grammar question

Factual Questions
1

Quote from Wapo online (my emphasis)

President Obama will face an divided Congress in his first prime-time address this evening but polling suggests he and his administration are already receiving a far warmer welcome from the American public.

I’ve seen this treatment here, there and elsewhere - using “an” maybe sarcastically or whatever.

My question, is the “an” properly used, or is it just a typo.

2

It’s clearly wrong, and my guess is that the writer originally used an adjective starting with a vowel, then revised to “divided”.

3

My suspicion as well. Had to ask, though.

Thanks, Giles.