When you look at different takes on the Darfur situation, you see them divided into two main camps. On the one hand, you have people who are interested in Darfur who don’t normally write about humanitarian issues or Africa, but who do frequently write in support of militarism and in derogation of the UN. In this camp you have Kirchick, The Weekly Standard, Leon Wieseltier, Marty Peretz, etc. These people believe, naturally enough, that unilateral American military intervention in Darfur is the only responsible option. On the other hand, you have people whose interest in Darfur stems from a larger interest in humanitarian issues and in Africa. I’d take the International Crisis Group, the Enough Project, and Africa Action as typical of the latter. If you follow the links, you’ll see that none of these organizations think that what Kirchick is saying about this is correct.
Meanwhile, as Kirchick himself notes, Obama is pretty close to Samantha Power who wrote the book on genocide. Like the people in the second camp, she’s a skeptic about unilateral military intervention as the prime tool of fighting genocide. Indeed, she explains in the book that she thinks this kind of Kirchick-style thinking is counterproductive; sending people the message that if you care about this issue you need to sign on for a costly and geopolitically problematic military intervention leads far more people to say “I should stop caring about this issue” than it leads to say “I should support a costly and geopolitically problematic military intervention.” Thus, they favor thinking pragmatically about actions that might realistically be implemented.
The difference, though, is that if you’re more interested in wielding Darfur as a bludgeon against liberals, the UN, Arabs, etc. than you are in saving people’s lives, this kind of pragmatism becomes less appealing.