Doug Wilson on the differences:
It is easy to send up the precisionist logician, but the mockery only works effectively when the satirist is being a better logician, making more careful distinctions. If the mocker is making less careful distinctions, then he is the one whose seat we were told to stay out of (Ps. 1:1).
The godly satirist is one whose joke depends upon a sound argument, and would not work without it.
The ungodly mocker is one who assumes that the case has been made somewhere, by somebody, and proceeds straight to the laughter. Mockery of this sort is the laugh track of unbelief.
When ridicule is substituted for argument, the result is thorns crackling under a pot.
When the argument leads inexorably to ridicule, then a man is not a true man if he does not laugh at the man who cooks his dinner with this end of the log and carves a god out of the other end of it.
Read the whole thing as he explores this a bit more.