Watching reactionaries try to defend it is almost as funny. Endless verbiage to make one simple (yet dumb) argument: "the scientists need to be paid by somebody, so why not Exxon?"
The answer, equally simply? Because they aren't being paid for their insights, they're being paid for having the "right" results. For all that these "Big Lizards" tools fulminate about leftie academics, no university does this, and reputable think tanks don't do it either. They might pay for researchers to do work about subjects they agree with, and might even hire ideologically-compatible researchers. What they don't do is buy results. If, say, Brookings gives a research grant to a Ph.D, they don't say "and make sure you come to the conclusion that Iraq was a fine idea".
They say "research Iraq and tell us what you find". At WORST they might bury poor results, but that is worlds different, and while researchers might not get future grants from, say, the Sierra Club, you'd have to be profoundly naive to think that they couldn't find an employer.
(Like, say, the AEI!)
And Universities are, of course, different beasts entirely. The whole tenure system exists because this very idea of paid results would cause 99% of legitimate academics to break out in hives. Academics tend to become more successful by going against received wisdom, not for it.
I realize that this is a terrible day for the right blogosphere- the IPCC smacked down pretty much every argument by the deniers and the AEI has just been thoroughly discredited. Still, you'd think they'd do better.