I read and saw this:

The story involved allegations that Barack Obama’s campaign, in league with Acorn, a left-leaning community activist group, was guilty of technical violations of campaign finance law. Evidence supplied by the source could not be verified. Even if the story had panned out, it is hard to see how any editor could have regarded it as momentous enough to change an election in which the Republicans were saddled with an unpopular war and an economic meltdown.

If the evidence could not be verified they should not have run the story.