John McCain didn't just fail to get the game-changer he needed -- he was trounced in this third and final debate, if the instant post-debate polling provides any indication.

The results over at CBS show Obama to have scored the biggest victory to date: "Fifty-three percent of the uncommitted voters surveyed identified Democratic nominee Barack Obama as the winner of tonight's debate. Twenty-two percent said Republican rival John McCain won. Twenty-four percent saw the debate as a draw."

It is, the site writes, "a clean sweep" for the Illinois Democrat.