Cobrakai spelled out my thoughts pretty precisely. There is a lot of competition for top 20 programs. After going through the whole application process this year I was really surprised by how hard it is to crack that top tier when you have a blemish like a low GPA on your application.
Just to share my profile and application experience: I'm a 27 yr old white male. I have solid work experience, lots of community involvement and service, international experience, and I got a 780 on the GMAT. I also hired an admissions consultant to help me put together my applications. My one weakness was my GPA, and it isn't bad compared to yours - it was a 3.2 something. Anyway, I applied to seven top 20 schools, three in rd 1 and four in rd 2. I was auto dinged at Kellogg and Columbia. Waitlisted at Fuqua, Ross, UCLA and Darden. Accepted to McCombs, with a scholarship which I'm grateful for, but I really thought that would be my backup. Maybe I just had bad luck, and perhaps I'll still get in off the waitlist to one or more schools, but my point is that it's very competitive. Try to keep an open mind as you research schools.
I do agree with CobraKai on the top 16. I think if you ace the GMAT and execute your apps perfectly, you might have an outside shot at a school in the range of 17-25. But I'd suggest you figure out what your goals are and where you want to live after school and find some solid regional programs that align with those goals. Because a 2.37 is going to be very tough to swallow for any top tier school.
The only other thing that you can really do to offset the GMAT is build an alternate transcript. Take some quant or business focused classes such as Econ, Accounting, Calc, Stats etc. And of course get A's in them.