There is perhaps something to say about rhetoric and tactics. Bruenig's profile has reached boost phase in the lefty political sphere because of his extraordinarily sharp analysis, his frankly unmatched ability to cut through decades of political derp to the core of an issue, and his background coming from poverty (which is very, very rare in elite punditry of any stripe), especially the insights thus constructed. He's got this coldly brutal intelligence and style that is equal parts effective and fearsome.
Conservatives, libertarians, and many centrist liberals tend to hate him, though, which isn't so surprising because he tends not to give quarter to the mistaken. And against the class-privileged writers of condescending thinkpieces about the poor, he's absolutely merciless. I don't come from nearly the kind of poverty that he does, but I'm also a lot closer to his background than the average DC journalist, and personally it's hilariously satisfying to watch a skilled analyst dish out these bougie vivisections.
I don't do much of kind of stuff so much anymore, though (well ok, not unless the target is really ripe), for a variety of reasons. First, I'm not nearly as smart as Bruenig, and if you're going to be that confidently aggressive you just can't make dumb mistakes. Second is personality; I'm pretty conflict-averse and don't like heated arguments. Third is also that along the road is that I've made a few conservative friends and I don't want to just bludgeon them and sever that friendship while almost certainly not convincing them of anything.
And fourth, I basically believe in the importance of politics based around logic and argument, despite how much the very concept of "civil" debate is perverted by centrist swine like Lanny Davis. Though it's certainly not anything close to enough to build a political movement, I think it's a way to keep one's own side and mind sharp and free of bullshit derp, as well as an extension of a bit of decency to my fellow human beings, who haven't had the experiences I've had. Whatever, people's priorities can differ on this kind of thing.
The question that I'm not certain Bruenig has completely grappled with is just what he wants to achieve with this kind of writing. The problem with attacking someone's background is that they and all their friends are going to close ranks and raise the psychological barricades. They won't even engage with the substance of your argument, instead they'll blast you with squid-ink BS, attack your background, or just simply refuse to read your stuff on the grounds that you're basically equal to a white supremacist.
Whether that's bothersome or not obviously depends on one's goals. If you just want to make them look like an asshole to your comrades then no problem. But if you want to convince someone they're very badly wrong then in my experience you've got to stick rigorously to the content of their position and scrupulously avoid any comments on their personal life or value as a person. As with mathematics, learning one has a wrong belief is very difficult, and is just about impossible with much self-doubt, anxiety or stress going on. Is that worth doing? Well, I dunno, maybe?
There's also a matter of argumentative power. You could also view sticking very scrupulously to the argument (Rich Yeselson is very good at this) as a source of rhetorical power itself, by not allowing your political opponents the kind of psychological escape routes you might otherwise provide.
There's also a career angle to consider. As Bruenig continues up the ladder there's a decent chance people who've been shanked by him will to mobilize their relationship networks and try to sabotage his career and prevent him from getting more influence. Of course, outright muzzling oneself for the sake of money or status is ethically monstrous. On the other hand, it might be worth setting the value of including among one's major point (McArdle is wrong about poor people) a pretty cutting attack against a person's identity (McArdle was heavily subsidized by her parents and failed at business) against the probable damage it might do to one's future prospects for influencing the course of political events. In this instance I'd say it's justified by any metric you'd care to choose, though I might have toned it down slightly.
Of course, on the other hand, there are countervailing advantages of many kinds to being known as a skilled takedown artist; many have built their careers around it.
Now, maybe I'm wrong and Bruenig has thought through these things very carefully, or perhaps I'm already a sellout DC hack, but in any case I think these questions of power are worth thinking about tactically and strategically, and I think a lot of lefties abandon them for a sort of pointless holier-than-thou purism. (Not Bruenig, to be clear. He's also worked for a union and other activist groups, which is probably worth more than a round ten billion blog posts—certainly more than I've ever done at least. In any case, I've got a longer piece on these issues almost ready for this space that I'll hopefully publish sometime this week.)
He's said before half-jokingly that this whole business is nothing more than infotainment for the upper-middle-class, but that's a tough position to defend in seriousness. Though it probably increases my hack score some more, I think Chris Hayes has navigated these shoals about as well as any lefty could expect, and has achieved some real, positive influence as a result. I also think the difference between the way conservatives react to Steve Randy Waldman and the way they do Bruenig is pretty striking, despite the fact that the two have similar positions on many things.
It is of course preposterously unfair to be talking about the poor, poor hurt feelings of class-privileged media elites who get walloped in the same terms that they constantly deploy against poor people, and many if not most elites are stone hypocrites on this issue. But while I shed no tears for McArdle, I do think it's taking some time to think about rhetorical strategy on occasion. In itself, being right isn't worth much.