Deborah Fleischaker, director of state legislative affairs for Families Against Mandatory Minimums, has this piece at Jurist:

[T]here is no evidence to suggest that repealing mandatory sentences would lead to an increase in crime. In fact, states that have significantly reformed mandatory minimums, as Michigan did in 1998 and 2003, have not experienced increasing levels of crime. More and more states – notably, both red and blue states – are employing proven alternatives, such as drug courts and risk-based sentencing policies, which are more effective and cost-efficient than lengthy, mandatory sentences, especially when dealing with non-violent drug offenders