However, my point is that certain things other than the truth or falsity of such propositions are directly relevant to whether a given policy should be implemented in a democratic society. And one of those things is whether it was procured by corruption.

So my statement “the bankruptcy bill was procured by near-bribery,” for example, or the example above, “that study was bought by the power industry” does not directly impact the merits of the bankruptcy bill or the study. However, it does tell us that there’s a countervailing consideration against implementing the bill or the recommendations.

(My point works much better with my purchased legislation example than the purchased study example, admittedly.)

It’s sort of like the exclusionary rule. If the police search someone’s house without a warrant and find evidence of illegal activity, we don’t let them introduce that evidence at trial — even though it’s probative on the issue of the guilt or innocence of the criminal — because we’ve made a decision that it’s more important to keep the system clean of the misconduct that procured it. Much the same could be said of bills, studies, commentary, etc. produced by corruption.

Suppose you’re the president, and a bill comes to your desk with the following history:

- I stole $2,690,000 from the public via a massive scam and used that money to bribe a majority of Congress (at 10k a pop) to pass this bill.
- The bill taxes every American two dollars and gives that money to me.
- The bill requires me to use half of the money to build a new road between Washington D.C. and New York, which is badly needed.
- If the government built the road itself, it would cost a billion bucks.

As president, should you sign this bill?

I say no, because, even though as a matter of pure economics, the public benefits (the net of my ill-gotten gains is less than the cost savings from the needed road), it’s obtained by corruption. And the passage of a bill obviously obtained by corruption injures the strength and legitimacy of the democratic process.

Corruption, which is what “ad hominem source of funding” attacks are usually directed at, is itself a social ill for which no quarter should be given, and which may itself recommend against policy proposals.