I think it would depend on how intense and long your cardio is. If its just like a five minute ride on a bike for like a warmup id did it before but if its really intense and longer def after because you want as much energy for you weightlifting as possible..
Doing cardio after will be more beneficial to YOU. Especially if you want to have a good workout. Think about it....if you bust your tail on the cardio machine for 30-45 minutes BEFORE your workout...do you not think that would take away some of your strength for the real workout???...the one that actually MAKES you stronger???
Just food for thought....
I either do mine in the mornings...separate from my workout all together...or I do it after my workout....never before.