"That's not true."

If Sen. John McCain said during the debate that the grass is green, Sen. Barack Obama would reply saying, "That's not true."

Here is the debate in a nutshell with the response from Obama:

McCain says that Obama's campaign was launched at Bill Ayers' living room: "That's not true."
McCain says Obama's tax plan is socialism: "That's not true."
McCain says that Obama is for killing babies after a failed abortion: "That's not true."

All the statements above are true and anybody who has access to a respectable newspaper or to the internet can see for themselves that these statements are true.