What's your current role? Is it with the consultancy companies you mentioned in WE3? If I were you, I'd keep the current role and not switch. Nobody likes to know that you're jumping around and have 4 different jobs in 4 years. It insinuates that you cannot commit. So rather than taking this government job, I'd stay at the Big 4 (unless you're not enjoying your work anymore, then that's a different story). One thing I do want to mention is that it is really not about the number of years or the titles you have, but more about the quality of your work experience that will differentiates you among all other applicants. If this government job allows you to work with Obama, that work experience will be VASTLY different from most of the other applicants. It's hard for someone to tell you which way you should go, since ultimately you're the one living the consequences.
In terms of suggestion, if you're looking at consultancy, check out Kellogg, Tuck, Ross, Darden, and Fuqua. These schools are strong in placing students in a consulting firm. Of course, you can go to any top b-schools and enter consultancy, but these schools tend to place more, that's all. Good luck!
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