The rocky Obamacare rollout have sparked a big, raucous debate within lefty precincts over how far to go in criticizing the problems that have plagued the law. On one side, liberal wonks — like Ezra Klein and Ryan Lizza — have been harshly critical of the rollout and of the administration for making a mess of things.

On the other side, people like Joan Walsh argue that the criticism has exaggerated the problems and enabled the right’s campaign to destroy the law, while Zerlina Maxwell added that the privilege of Ezra and company — as already-insured Americans, and as men — have distorted their perspective on the law’s problems.

This discussion matters because it’s a small example of a larger phenomenon on the left and internet culture generally: the tendency for discussion to get swamped by unnecessarily personal argument, when large political battles with big stakes are underway.

Here’s Zerlina:

…when you defend your negative reporting about the Obamacare website glitches, as The Washington Post‘s Ezra Klein did last night on MSNBC, having the privilege of analyzing the process from the perspective of someone who is already insured and not in need of coverage allows the core impact of the new program on the health and security of millions of Americans to be missed…while some young men may think they are invincible and don’t need health insurance, preventative care is not something that the majority of women can roll the dice with…unless you are a journalist who has been chronically uninsured, your feigned frustration about website issues reeks of privilege. To me, a few website glitches are a lot less frustrating than having to use the same inhaler for over a year because I can’t afford to go the doctor. Perspective is everything.

Let’s get this straight first: invoking privilege is a powerful weapon because it is a very real thing. White men are, for starters, the overwhelming majority of guests on cable news, the overwhelming majority of corporate board members, and the overwhelming majority of political elites. This despite the fact that this year, women will make up 57 percent of 4-year graduates, a trend which is still increasing. It beggars belief to imagine that this discrepancy is the result of anything other than entrenched perpetuation of undeserved privilege.

But attacking someone’s position because of their privilege is practically the dictionary definition of an ad hominem argument. It says: you are too blinded by your cosseted existence to see what is in front of your eyes. One can’t possibly disprove an allegation against one’s ability to understand. It’s not surprising that people are a bit touchy about that kind of accusation, and tend to react defensively.

This is not to say that throwing the “privilege” flag should be banned outright. I would suggest instead that it should be reserved for cases which definitely merit its use — and that means, at a minimum, providing some evidence of clouded vision. Many privileged people have managed to look past their own comfort — FDR, for example, was as privileged as they come.

For the record, I think Zerlina is a great writer and journalist. I was hugely impressed with her appearance on Hannity, and the way she bore up under the ensuing deluge of racist trolls.  Online discourse (as she well knows), especially Twitter, can be so unpleasant already. People who have earned a little generosity, as I believe Ezra has on health care, ought to be given the benefit of the doubt. Not that he is beyond reproach, but that criticism should not be immediately personal.

This is just a window into a larger tendency. I often see people who are inches apart on the issues arguing heatedly over basically trivial disagreements. I’ve done it myself, and regretted it every time. The left has always had a chronic problem with staying united, and this is no exception. Let’s try to keep the liberal house as free of unnecessary bitterness as possible.