Changing Visitation With a Delinquent Parent

My question involves a child custody case from the State of: MI
9 Year old daughter. I have primary custody. Currently arrangement is every wed 5-8 and every other weekend along with 6 weeks of summer.

My ex has always been an alcholic but that is hard to prove. I have always had a court order that he cannot drink 24 hours prior or at anytime he has her but that is very hard to prove.

Within the last three years him and his girlfriend have broken up no less than 30 times. I have a police report where she reported him for domestic abuse but I beleive no charges were filed. He also is on his third drunk driving charge in 3 years.

Shouldn't this be substantial reasoning for reducing his visitation rights????

Oh and by the way I am a law abiding citizen with no record and have been remarried for three years.