From the Post's write-up of the Glenn Beck rally, here's the only mention of the crowd size debate [emphasis added]:

The size of the gathering promises to be a subject of contention. Demonstrations on the Mall are notoriously difficult to estimate, with no official source for such figures. At one point, Beck joked he had “just gotten word from the media that there is over a thousand people here today.” Later, he told he [sic] crowd he heard it was “between 300,000 and 500,000.”

Rep. Michele Bachmann (R-Minn.), speaking soon after the Beck rally at her own impromptu event nearby, said: "We're not going to let anyone get away with saying there were less than a million here today - because we were witnesses."

So if you read only the Post account you'd think that the point of " contention" was between conservative Beck (500K!) and conservative Bachmann (1M!).

But of course, the contention stemmed from skeptics who wondered if, like Tea Party organizers in the past, Beck and his allies would simply concoct the size of the rally. Y'know, the way Tea Party fans claimed 2M people marched on Washington, D.C. in Sept. 2009, when in fact, according to fire department estimates, just 60-70,000 people marched.

Oops.

And sure enough, according to an outside firm hired by CBS News, the only independent and semi-official estimate of Saturday's crowd was pegged at 87,000. (Or about 900,000 less than Bachmann's claim.) But the Post forgot to include that in its article. Instead, the Post simply allowed Beck and Bachmann to pull crowd size numbers out of thin air.