Major GPA doesn't matter. The only thing that matters is overall GPA. Back to the discussion of "fluffy" majors, it really makes no difference, as long as the major is something that is somewhat respectable. I think you may run into some problems if you major in "basket weaving" or "ballroom dancing" (and that's probably if you didn't graduate with a 3.7 or above).
I think, for some reason, liberal arts majors tend to get a lot of unwarranted flack. They are seen as "easier" than other majors; but there is a reason that these majors tend to be seen as good for law school preparation (majors such as political science, philosophy, English, etc.). They help a lot with developing writing skills and honing analytical ability (not that other majors don't; it just seems that these majors may be better suited for the task).
I recently was cleaning out my hard drive and I was looking over some papers I had written freshman year; I contrasted them with papers from my last year, and I could marked improvement. Of course, you may want to argue that improvement could've been as a result of just maturing in my years, and not a correlation with my course of study. However, I'd disagree. I studied political science and philosophy, and I can say with confidence that my philosophy courses truly helped hone my writing ability that it translated over to my political science papers.
In the end, I just want to state that, though some majors are seen as "fluff," they do help foster many beneficial skills for law schools. I think adcomms are aware of this fact. I took a sociology class to fulfill a requirement; i rather enjoyed it.