Is there a good moral argument against moral realism?

In connection with my project on expressivism and normative realism, I have been working on a paper that examines some recent arguments according to which there is something morally objectionable about moral realism, or normative realism more broadly.

When I started working on this paper, I was inclined to think that some of these arguments might indeed be effective against robust realism, i.e. the kind of realism that treats metaphysical claims about normative facts and properties as irreducible to first-order normative claims, but not against the minimal realism that I favor, on which such seemingly metaphysical claims are interpreted as internal to normative discourse. However, I have changed my mind on this issue. I now believe robust realists can successfully respond to all versions of this moral challenge, at least if they adopt a certain stance on how we should metaphysical beliefs about morality or normativity.

Here is a presentation of this paper that I have prepared for the 2020 European Congress of Analytic Philosophy, which is held online because of the COVID-19 pandemic: