Nathan Robinson has an insightful post worth linking to.
The problem with “we,” I think, goes beyond just a cheap rhetorical trick to subtly coerce agreement on the interlocutor. It is a signal, that, both “you” and “I,” subscribe to the creed X: you believe X, I believe X, we all believe X, in other words. A reminder that these are the things that define “our tribe.” It CAN be a cheap rhetorical trick to subtly coerce agreement: you are a respectable person, right? so you must believe X, too. But this is not necessarily always the case. In a sense, it is like an exchange of passwords and secret handshakes: if I say “Lord be with you,” you should know to say “also be with you.” (If you don’t know what these mean, or worse, if you think they are out of date, that’d be the point–knowledge of these things indicate both membership in a given tribe and the timing thereof. In other words, they are reminders that all participants in the conversation subscribe to the same shared narratives–where the sharedness, and the implicit trust that accompanies it, is more significant than their factual accuracy. (Indeed, one might say that a willingness to subscribe to things that aren’t actually true indicates a greater trustworthiness–costly by credible signals and all that.)
Of course, the reaction to the “we” can easily be “What do you mean ‘we,’ white man?” (to quote from the Lone Ranger.) This is the reaction from the people who don’t share the common narrative. Without the implicit agreement, you and I ain’t “we.” So the rhetorical use of “we,” counterintuitively, divides: there are many “we’s,” without shared focal points among them. We, in a manner of speaking, cannot climb over the barriers between the many “we’s” without trying very hard to understand beyond our “we,” and this is increasingly getting harder as technology makes it easier to retreat into the company of our “we’s” alone.