I think many creationist "activists", including most of the people who work at Answers in Genesis and other similar organizations, and people like Kent Hovind, don't really believe in creationism. Most of them have been exposed to too much literature about biology and paleontology to be able to deny common descent (at the very least). But, they've found a way to make huge amounts of cash by writing pretty much anything they like, without doing any research or real work, and they don't even have to be particularly convincing, because the tens of millions of people who buy their stuff will keep believing in creationism because it's a belief based on emotion, not reason.
The same is probably true of Michael Behe (the guy who wrote Darwin's Black Box). I'm pretty sure he doesn't believe his own "theory". He's a really sly one, though. He's walking a fine line between science and supersition. On one hand, when he's talking to real scientists he'll assure them that he accepts common descent, but on the other hand, when he's addressing creationists he'll spout crap about ID and irreducible complexity. By doing that he keeps himself from looking like a complete nut in the scientific community, but he makes oodles of cash by selling his books to morons. It's a pretty sweet deal.
Cameron is doing the same thing, except he doesn't care about being respected by the intellectual community, he's ready to do anything to fill his pockets.