Specifically, the term "creationism" is inadequate. What we really mean here is "Christian creationism." That puts a finer point on it, and lets everyone in the conversation know exactly what we mean. I think it even exposes the proponents of it to some enlightenment on what they're really saying.
I think an argument has more weight when you say, "Do you mean to tell me that you want Christian creationism taught instead of evolution? Do you think other religions' creationist ideologies should be taught as well?"
From now on, every time I get caught up in this argument, I will use the term, "Christian creationism," and not just "creationism."
The term "evolution" is inadequate. What we really mean here is "atheist evolution." Now we can see the argument is really, "Do you mean to tell me that you want creationism taught instead of atheist evolution? Do you think aetheism should be established as the national religion?"