Hi onlysaneman! Thanks for airing your concerns.
Our math is admittedly rusty, but we’re not sure why this wouldn’t qualify as a valid Venn diagram, given that it describes one member of a set that represents the logical intersection of two greater sets. The proof (again, we’re rusty) is something like this:
It’s logically possible that there are other members of the intersection of A and B, so it might mislead a bit to suggest that Romney’s the only element in the set. But he’s undeniably in it. Right? QED?