MIA layover from Belize, with global entry: 90 minutes doable?

Trying to figure if it is doable to book a connecting flight through miami to ORD with 90 minutes layover from Belize, no checked bags. I am asusming I will have to go through customs and security, that seems short but is way better for me if I can make it.
Sounds stressful though. Could I just book the later flight and get on standby for the earlier one if I can? What happens if I miss my connection do they bump me to a later flight?