Ad hominem is more than just name-calling. Ad hominem is a logical fallacy. It is a logical fallacy to say "that person's statement is false, because he is an X." It can happen explicitly or implicitly.
It's not a logical fallacy to say that a source of "information" has repeatedly demonstrated a calculated attempt to misrepresent the facts or even a pathological indifference to truth. Nor is it a logical fallacy to call one who has lied a liar. I'm not even sure it's name-calling. Of course I'm aware that personal perception plays some role in this - but it's also true that some people lack integrity. That some people are at least genuinely, if profoundly, mistaken does not mean that liars do not exist.
Calling one's self "fair and balanced" does not make one "fair and balanced." Calling one's self a skeptic, does not make one a skeptic. I think there's no better word than denialist in some cases (unless it is rejectionist), but I would settle for the term "doubter."
Even someone who comes to accept or reject a particular view can still be considered a genuine skeptic to the extent that she is willing to examine critically evidence contrary to his previously conclusions. But someone who makes up their minds - before they understand the least little details of the matter - that person is not a skeptic, regardless of belief or disbelief.
