The Wonkette piece makes it clear that this class exercise was to get kids to think about what symbols mean and how they're used, not to indoctrinate kids into being leftists.
But, of course, the "conservative" mindset these days is that to learn about anything not in the Rush Limbaugh Canon is to conjure up Voldemort or Ha-Satan or the Krampus. The only way to protect sensitive minds is to only tell them "conservative" doctrine. That's why the word "gay" can't be used or discussed, either.
Gotta keep the Fox News viewers riled up to keep them in line, you know.
It's pathetic, but there you are. :-(
Cheers,
Scott.