He was right, though. It was a misspelling. In that sentence, it should have been effect, not affect. At least in the US. I've got no idea whether that's one of those weird UK/US differences.

You have a point that he was probably being snarky by calling attention to it. We knew what you meant. In any case, one's ability to spell (especially in the case of a tricky homonym with a subtle distinction in definition like that one) is unrelated to their cited evidence in a political debate.