I agree with @csdad however I do believe ED gives applicants a slight edge. What you hope for is an acceptance, obviously, but would be OK with a deferral into RD. What you risk ED is a flat out rejection. Is your essay strong? Because that is an extremely important part of your application.
A 31 isn’t a bad score and it needs to be put into context within the college/program you are applying to. You should check out the Common Data Set for Cornell to see where you fall.