It's a long, thoughtful post, and you should read the whole thing, but the argument I find most compelling is the case Horace makes that as teachers we are public intellectuals, and ones serving a more important and diverse audience than those rare people who get published in The New Yorker.
As Horace notes, part of the problem with the argument that academics are overspecialized is that in our daily work lives, we rarely are: we teach survey classes, we teach texts outside our field, and we do, in fact, make big connections and address the concerns and interests of nonspecialists--our students--all the time. And most of us, Horace and myself included, aren't teaching the elites that Menand both teaches and writes for: we're teaching at state institutions, to first-generation college students or adults holding down full-time jobs and raising a family at the same time. Sure, we write on esoteric topics, but having an active research life means we're on top of the developments in our fields and can translate some of the most important ones for a lay audience (again: our students).
I agree with Horace that being a public intellectual in the classroom has political implications, the most important being helping to mold smart, thoughtful citizens. Horace writes,
While Menand wants a public intellectual who functions in the public marketplace, I want (and want to become) a different kind of public intellectual: the sort who engages the public sphere of our commonly owned government and governance. And for me that starts in the classroom, and in fact demands that I be the political provocateur that I sometimes become. I will tie Wordsworth's laments in "Tintern Abbey" to arguments over mountaintop removal. I will make clear that the imperial tactics in Heart of Darkness are primarily economic, and therefore still entirely in operation today in the under-developed world. I will note the particular nature of the construction of masculinity in Tennyson, and the ways that those constructions are still rooted to our sense of nation and empire as well as leadership and achievement. These are reading tactics that help my students translate the ideas of literature into the very practical world of their own.
Now, this is something that I do not do--make explicit political connections in the classroom, for reasons that I discussed in this post and its comments--but in a more general way I think that what goes on in my classroom can have both personal and political effects (though they need to happen in my students' own heads and lives, and on their own time): I hope that taking my class on sex and gender in the Renaissance enriches the ways my students think about those topics in the present day, simply by giving them a different cultural context and allowing them to think outside the terms and ideas that we take for granted.
But more generally, and maybe more importantly, by being public intellectuals in the classroom, we're modeling for our students what it means to be engaged by literature or history or art, and why those subjects might continue to matter and have relevance for them even once they're out of school. I think often about a comment a reader left on my blog, a couple of years ago, after I'd written about three former students who had collectively asked me out to lunch. I was trying to figure out whether they were looking for me to be a friend, or were thinking about grad school, or what--and my reader remarked that many smart young people are just looking for ways to be in the world, and that we often model that for them in ways we're not aware of.
That's not the job I'm paid to do, but it's one I'm pleased to perform, at least occasionally, whether I know it or not.