The "sponsor" - COMMISSION ON PRESIDENTIAL DEBATES
If anyone is a culprit it is the Commission on Presidential Debates who decided the criteria for [link|http://www.debates.org/pages/candsel.html|candidate selection.] Picking 15% of the poll vote as a minimum, I'll grant you, was not aa arbitrary choice. I would agree that a lower (but > 1) percentage would be better. You don't want a zoo either.
For Lehrer to have declined to be the moderator would be to become a news maker and not a news reporter. He would be making a political statement and raising a furor which would destroy the need to be impartial. What do you expect from the press or an umpire?
Alex
"Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing had happened." -- Winston Churchill (1874-1965)