"Prove it"

Jon Chait slags dKos for accusing the U.S. Chamber of Commerce of funding a "job security" group:

I didn't think anybody could make me feel sympathetic for the U.S. Chamber of Commerce. Nobody, that is, except Markos Moulitsas.

Chait quotes the Chamber's blog:

Last Friday Markos Moulitsas, the Kos in DailyKos, put up a fundraising post titled "AR-Sen: Hell to Pay: Chamber-backed group runs racist ad against Bill Halter." After displaying the ad the bulk of the post starts with "The group running this ad is funded by the U.S. Chamber of Commerce..."

Ok. Let's stop there, because the group "Americans for Job Security" is neither backed nor funded by the U.S Chamber, nor did we provide any funding for political or issue ads to them ...

To which Kos retorted:

Prove it.

Looking at the website of "Americans for Job Security," one learns that

Our members are businesses, business leaders and entrepreneurs from around the country. AJS does not disclose or discuss its membership further than this. Too often politicians or the media define an organization or message not by the merits of the argument, but rather by the perception of the people associated with it. We would rather the people decide on merits instead of name-calling.

On the one hand, the Chamber is surely right that it can't prove a negative. On the other hand, the AJS isn't telling who supports its quest for "job security," though employees seem to be notably absent from an endeavor that one would think they might find attractive.

So I'm a little less inclined than Chait simply to accept the Chamber's word here.