Fault Divorce in Michigan
It is true that Michigan is a no-fault divorce state. This means that you can file for divorce and get divorced without proving that your spouse is at fault. Michigan became a no-fault divorce state in 1972, allowing couples to end their marriage without proving that the other spouse had committed adultery, cruelty, imprisonment, or abandonment. Since the law changed in 1972, to get divorced you just have to indicate that there has been a breakdown in the marriage relationship, and your divorce can be granted.
However, that does not mean that fault is never considered in a divorce. And fault generally means more than just infidelity. It can also be based on domestic violence, drug or alcohol abuse, financial disaster (gambling, etc), or abandonment.
In Michigan, fault can affect three areas in divorce:
Division of property and fault
When it comes to property division, Michigan law requires that any marital assets (assets earned or acquired during the marriage) are to generally be split equally, with each spouse taking 50% of the marital estate. However, if one spouse is at fault for the marriage, the court can award more property to the spouse who is not at fault, moving away from an equal split. However, the general rule of thumb is that fault cannot tip the scales too much, and at least one Court of Appeals case indicates a 60/40 split is too extreme.
Child custody and fault
When a court is asked to make a custody determination, the court looks at 12 factors that are considered to be the "best interests" of the children. One of those factors is the "moral fitness of the parties." While this is only one factor out of 12, any issues of fault must be considered by the court if the court is to determine what parent should have custody of the children.
Alimony and fault
Finally, fault is considered by the court when it makes a decision about whether or not to award spousal support (alimony). The court must look at 11 factors in order to award spousal support, and one of those factors is the "past relations and conduct of the parties." Again, it is merely one factor, but fault here can be considered to increase or decrease a spousal support award.
So the short answer to the question is yes, the courts do consider fault in divorce. The long answer to the question is yes, but it is merely one factor that the court considers, and it does not outweigh any other factor the court must consider.