From that LAT poll of Florida of Ohio (here is the PDF with all the numbers):

Already Voted:

Florida: McCain 49%, Obama 45%, Don't Know 6%

Ohio: Obama 57%, McCain 35%, Don't Know 3%

That's right: Almost 5% of Florida and Ohio voters that have already voted don't know who they voted for.

(Maybe these folks were just unwilling to answer the question, but that isn't how the poll reads).

[Thanks to reader M.A.]

--Isaac Chotiner