Will’s post is here.
1. Will has on several occasions argued that when a critic points out a particular defect X or Y in originalism, the critic must also show that some other interpretive methodology does not suffer from that defect, or is not otherwise inferior to originalism. It takes a theory to beat (or outrun) a theory.
This is not exactly right, though it contains an element of truth. Some theories are so bad that one can condemn them without comparing them to others. The theory that justices should consult the Zodiac in order to resolve disputes is one. At some point, we will need to examine alternative theories and see how they measure up to originalism. But in the meantime, it is pragmatically implausible to insist that one must constantly juggle all the theories at once (how many?) in order to be justified in pointing out a problem with one of them.
2. Will says “I see our government strictly following the founding-era document a huge amount of the time.” The modern system of governance in this country is vastly different from what existed in the eighteenth and nineteenth centuries. If it is consistent with the text, that can only be because the text is so vague and full of holes, undefined terms, and so on. Any style of originalism that can accommodate the current system of government has hardly any constraining force at all.
3. Will says “I think many (though not all) invocations of originalism are sincere.” Frank Cross’ book is the most rigorous effort to test this hypothesis and he finds no evidence that originalism constrains justices. It may be, as Cross suggests, that this reflects motivated reasoning rather than insincerity, but the effect is the same. This is also a problem for Will’s claim in a more recent post that originalism can constrain judges.