Tom Blumer of NewsBusters caught the AP in the lie, building on an article at Breitbart News that showed that both Politico and the Wall Street Journal had reported turnout for Obama at the Sep. 21 event as 18,000--at an arena that only held 5,000 people.
Though the arena was nearly full--and local media reported that more were outside the arena--there is no evidence whatsoever that the 13,000 people needed to make up the difference actually showed up. No images of that crowd have yet been produced.
The AP's take: "The crowd of about 18,000 in a steady drizzle was the largest yet of Obama's reelection campaign." And yet the AP did not count the audience. Nor did the Wall Street Journal. Nor did Politico.
So where did the official-sounding number come from? The Obama campaign, according to Politico--which was the only one of the three that had the minimal integrity to report the source of the estimate (though not to challenge it).
When the mainstream media calls a crowd is "the largest yet," but overestimates it by a factor of three or even four, you have a pretty good idea of how far they are willing to go to re-elect their patron saint.