President Obama on Tuesday laid out a sweeping plan for criminal justice reform in America, calling for the end of mandatory minimum sentences for nonviolent drug offenders, a review of solitary confinement in prisons and a host of other steps.

Speaking at the NAACP convention in Philadelphia, the president said he’s optimistic that Republicans and Democrats in Washington, and in states across the country, will join him in undertaking a massive overhaul of the entire criminal justice system. He said more investments must be made in early childhood education and after-school programs so that children are less likely to break the law, and he called on Congress to revamp sentencing guidelines so that individual judges and prosecutors have more discretion and aren’t bound by mandatory minimums.