On September 1, CNN, which is sponsoring the September 16 Republican presidential debate, changed the rules on who should be permitted into the debate. The old rules said the top ten would be invited, based on an average of all polls from certain polling companies taken between July 16 and September 10. The new rules change the time period for looking at debates, to August 6 through September 10.

This shows that if enough criticism is aimed at debate sponsors, sometimes they do change their rules. Thanks to PoliticalWire for the link.