Wutang \$m[1]:i dont know how good of chance do i have to get into consulting firm since I don't have high gpa and didnt graduated with relevant major (political science). I wouldn't mind to do consulting and I am reading some case studies right now, but I just dont know how to get in.
I think GPA is the most important thing for undergraduate to apply those
big consulting firms. The second important thing is educational background. You don't need to have any fancy major but the "name" of your school definitely matters. Ex. Stanford with major in history can get into McKinsey. They value high GPA and school name. They need "smart" people from different kinds of backgrounds. So, when doing case interview, they don't care how much you really know about the specific industry they are testing you. What they want is to see how smart you are to analyze the case fast and get the key points on spot. Actually, there is no "consulting" or related major, right?
In addition to these big firms, I think there are still lots of small consulting firms. You may try to find some information from your friends or maybe university career resources.
Finally, I am not sure what "case studeis" you mean. If they are HBS cases, I would say forget them. They are not helping you for case interviews. You should buy books like "Case in Point" rather than HBS cases. They are totally different.
P.S.
Case in Point
http://www.amazon.com/Case-Point-Comple ... 0971015805