I don't believe that Leno, or Letterman, would claim that their shows are anything more than light entertainment, their intentions being to amuse people in a relaxing way at the end of a day and an evening with their comedic routines aimed at current events, political and otherwise, and movie star and sometimes zoo owner guests.  Dangerous?  You are the one who must be joking today.
In a message dated 4/1/2005 2:13:44 P.M. Eastern Standard Time, [log in to unmask] writes:
What I abhor is the trite that goes on as comedy or
satire. When a person like Jay Leno makes a mockery of
say, George Bush, what I observe is his calculated
appeal to the newspaper reading common man or the
regular TV watching guy.  Such an appeal is not only
crude but dangerous as well.  The laughter that he
provokes is a consequence of having scratched your
subconscious ego to your pleasure and not because of
any possible humor as related to the issue.  After
watching him, you don’t become more conscious of the
issue; you only tend to be less conscious of it.  Or
that you find any further justification for an issue
or an object to be mocked.  Whereas, with a writer as
Swift and Mark Twain, it is exactly the opposite. 
They sure didn’t have the ‘intended’ effects in their
mind (it is interesting to note here that Dickens was
thought to have had it in his mind in quite a few of
his works).