So respond before the respondent gets a crack at this. But I don't go to synagogue enough, so for me Judaism is either social justice or a weak combination of chicken soup and neurosis. So here goes.

The core problem with Mr. Weiss's argument (may I call you Steven?) is his insistence on perfection by modern definition. I'll make an analogy. Gerald Ford was praised left and right for being an all-American football player for Michigan.  By modern standards, the guy was tiny.  Any 300 pound college lineman would toss a player his size aside like a sack of potatoes.  And any 350 pound pro lineman would toss that college lineman aside in the same way.  But would you deny that any of their "core defining traits" is "football player?"  

Back to Judaism: Even taking your narrow definition of social justice as "equality" and "wealth redistribution" (i.e. monetary equality), we did a great job at it when no one else was even trying. Leaving the corner of your field for the poor? It was an invention. We were some of the the best wealth redistributers in the world. We were the Gerald Fords of our day.  Same thing with equality. We started with a caste system, just like many other ancient cultures. But eventually the priestly caste became the rabinnic meritocracy (I'd call inhereted rabinates the exception, not the rule). 

And then the world changes. If our definition of social justice has changed, so must our expectations - because of Judaism, not despite it. We realize now the importance of equality for gays and lesbians, when we didn't realize it before. Rather than using that advancement to write social justice out of the picture, let's use it to better the core of our collective identity - define ourselves by principle not practice.  And even if there's a pro out there somewhere who could kick our butts, Massachusetts maybe, it doesn't mean we should stop trying all together.  

Moreover, your initial dismissal of the famous quote from Deuteronomy is less than satisfying. Sure, the Justice we should pursue is a learned judge. But why? Because at the core of all this is a notion of both legal and ethical right and wrong, and we should recognize the uniqueness in that notion, the iconoclasm in a world at that point defined by the triumph of power, not law. Maybe the law itself wasn't perfect. I don't plan on stoning my disobedient children some day or sacrificing many animals. But it was good. Or at least a good start.

- dan

PS - "Jewish hipster": If you're out there, I want to know where I can get one of those t-shirts.