Some people truly are the epitome of stupid.
Sometimes I laugh right at them when they say stupid things. When they ask why, my reply is usually along the lines of "Just remembering why I don't want my kids in public school". Of course no one ever gets it, but I do
There really is no point in arguing or even discussing with some people. Though I love a good discussion as much as the next person. There are some people, and some topics, that it's not worth the breath or time you take. Shame, really, but what can you really do? Some folks just aren't open for being educated.