Why the sudden change of heart?

Seems to me they had this one lined up to go to use against Bush as well. We can only speculate why it was pulled:

NEW YORK - CBS News has shelved a "60 Minutes" report on the rationale for war in Iraq because it would be "inappropriate" to air it so close to the presidential election, the network said on Saturday.

The report on weapons of mass destruction was set to air on Sept. 8 but was put off in favor of a story on President Bush's National Guard service. The Guard story was discredited because it relied on documents impugning Bush's service that were apparently fake.

CBS News spokeswoman Kelli Edwards would not elaborate on why the timing of the Iraq report was considered inappropriate.