The conclusions themselves aren't especially interesting; they're expected from a report with partisan aims. But the method used to reach those conclusions is often striking: The Republican majority engages in a process of systematically changing the standard of evidence needed for it to reach a conclusion. For a conclusion the report's authors favor, they'll happily accept evidence from computer models or arguments from an editorial in the popular press; for conclusions they disfavor, they demand double-blind controlled clinical trials.

This approach, which I'll term "shifting the evidentiary baseline," shows up in many arguments regarding scientific evidence. But it has rarely been employed quite this pervasively. So let's take a look at it in some detail and examine a few of the other approaches the report uses to muddy the waters regarding science. We're likely to see many of them put to use in the near future. //

So how to handle the disproportionate amount of evidence in favor of a hypothesis that the committee didn't like? By acting like it doesn't exist. "By nearly all measures of science, if there was evidence of a natural origin, it would have already surfaced," the report argues. Instead, it devotes page after page to suggesting that one of the key publications that laid out the evidence for a natural origin was the result of a plot among a handful of researchers who wanted to suppress the idea of a lab leak. Subsequent papers describing more extensive evidence appear to have been ignored.

Meanwhile, since there's little scientific evidence favoring a lab leak, the committee favorably cites an op-ed published in The New York Times. //

Put differently, even weak scientific evidence is preferable to a New York Times op-ed, yet the report opts for the latter.

This sort of shifting of the evidentiary baseline has been a feature of some of the more convoluted arguments in favor of creationism or against the science of climate change. But it has mostly been confined to arguments that take place outside the view of the general public. Given its extensive adoption by politicians, however, we can probably expect the public to start seeing a lot more of it.