By this we mean that grandstanding is a use of moral talk that attempts to get others to make certain desired judgments about oneself, namely, that one is worthy of respect or admiration because one has some particular moral quality—e.g., an impressive commitment to justice, a highly-tuned moral sensibility, or unparalleled powers of empathy. To grandstand is to turn one’s contribution to public discourse into a vanity project. Justin Tosi & Brandon Warmke "Moral Grandstanding" (3) [HT Kevin Vallier; & Brian Leiter]
Tosi and Warmke are to be warmly congratulated for taking on moral grandstanding; a topic that deserves serious scrutiny. Unfortunately, they take for granted that vanity is a vice. I use 'vice' because they use the language of virtue liberally and at one point they seem to identify their approach with virtue ethics (23 with an explicit reference to Aristotle); but it's okay for what follows if they are not virtue theorists. Crucially they think vanity is a bad-making motive to action. Now, it's true that Aristotle thinks that vanity is a species of foolishness. But his reason for this is that he understands vanity as the product of a mis-match between self-perception and reality; it is an excessive form of pride (based, in part, on something like self-deception/flattery). He is, thus, not against pride as such (which does not involve such a mis-match). Aristotle is not against acting from the desire of recognition as such, but it needs to be merited recognition (that is, pride).
Now, 'vanity' still can mean excessive pride or conceit. But it can also mean something like ostentation occasioned by ambition or pride. That is, it can be an excessive public display of one's pride. In cultures that emphasize modesty and humility (say because they are inspired by certain branches of Christianity) lots of things will be thought vain that may well be based on justifiable pride. If one rejects -- say with Hume -- the so-called Monkish virtues, then species of vanity that involve public displays of merited pride may well be thought good. And while this is a simplification, Hume defended vanity not only because it may well be merited but also because it could have many social functions not the least of which was to help generate and cement political communities. As Hume puts it: “Vanity is rather to be esteemed a social passion, and a bond of union among men”; (T 220.127.116.11) in context, Hume is explicit about the political significance of the passion (it is key to the whole system of property relations).*
More important, and this is to turn from Hume to Adam Smith (who was less a friend of vanity than Hume was, and not uncritical of Hume,* although he also saw that vanity could be functional), if the desire for public recognition springs from a desire for praiseworthiness (so not merely praise) that is, the "real love of true glory," then it is extremely admirable. (That is, Smith thinks it a mistake to call this 'vanity' but the desire for public recognition is not mistaken.)* So, if there is a problem with grandstanding it is not sufficient to show that a (vain) desire for public recognition is an important motive to it. So, for Smith there really is no problem with public expressions that are "attempts to get others to believe that one is morally respectable." (7) The desire to be seen to be morally respectable is not problematic as such. It can, in fact, be extremely functional in order to maintain public norms (as Hume suggests) or it can spring from extremely noble motives (as Smith suggests), or both. I return to the Humean point below.
As an aside, at one point Tosi & Warmke make it very easy for themselves because (in context of trumping up), they also suggest that "If grandstanders are eager to show that they are morally respectable, they may be too eager to identify as moral problems things that others have (correctly) taken to be morally unproblematic." Well, yes, but the problem here is not too much love for public displays of moral respectability, but rather its mistaken object (i.e., things that are taken to be moral problems, but are evidently (says who?) not.)
Okay, finally, a more subtle point. For the sake of their argument, Tosi and Warmke make the following distinction: "We do not intend to draw a sharp distinction between public and private moral discourse, but roughly speaking, public moral discourse involves communication that is intended to bring some moral matter to public consciousness. This is in contrast to typical private moral discourse, which usually involves communication not intended to be consumed by larger segments of the moral community." (4) Let's accept their distinction for the sake of argument.
They then go on to claim -- and this is crucial to many of their consequentialist concerns about the impact of grandstanding -- that "the core, primary function" of "public moral discourse" and "that justifies the practice is  to identify publicly certain moral features of a state of affairs, and  sometimes additionally to explain the evaluation of that state or  recommend some fitting response. In short, the aim of public moral discourse is  to improve people’s moral beliefs, or to spur moral improvement in the world." (16) I'll assume that  is the core idea here of public moral speech. (If I am wrong about that insert simply 1-3 in what follows!) They think this so obvious that, as far as I can tell, they never bother to justify the claim.
Private moral discourse may well have the core function they identify with public moral discourse. But it is a bit surprising for them to think that this is the core public function because unless one is already in the (normatively attractive, but empirically rare) grip of an ideal of public reason. But while it is conceptually not impossible, there are only a few instances in which public expressions of any kind have improved people's moral beliefs or generated moral improvement in the world (maybe MLK's famous "I have a dream" speech is the proverbial exception?).
Now, obviously if the grand-stander is a hypocrite, then in our age (which overvalues sincerity) there may well be reasons for censure. But one is not a hypocrite in virtue of either desiring public recognition or by using public moral discourse to express one's commitment to certain values. (Obviously, this is not to deny the charms and virtues of discretion or subtlety.)
For, none of this is to deny that public moral discourse can't be in the service of various moral norms. As Hume suggested, public speech is very important in maintaining and stabilizing various norms. But it does so not in virtue of sincere expressions of moral truths [that's really the road to fundamentalism], but rather by orienting our passions to proper objects. And people's willingness to publicly embrace certain moral commitments -- this may well become existential in the age of Trump -- may serve this end.** As Smith puts it,“The great secret of education is to direct vanity to proper objects." +
+ 'Education' can here mean public education.
**So, I am not denying that grand-standing can be oppressive in some contexts.