Dear Pat,

I think you have a chance at Columbia with an outstanding application package. You have a competitive profile; the challenge is can you craft a competitive application package that distinguishes you from the competition, makes a compelling case for your admission, and makes the admissions committee want you in the class. I'm not convinced a higher GMAT is necessary for you or that it would ultimately make a difference, but it certainly will not hurt you. If you have the time prior to the deadline, and it won't sacrifice the quality of your essays, then you could certainly retake the GMAT to try and increase your score.

Best of luck,
Lisa