It is not as clear cut as that at all. Wikipedia has a page on Denial..
What is "established" is part of the debate too and obviously it is in some deniers interest to instead label themself sceptic. Apparently there has been a debate about this:
Very great answer in those links, particularly the NCSE one. I'm not certain I agree with their conclusion, but the explanation makes sense and really answers a lot of my questions. Thank you!