On the road, O'Malley touts a string of progressive actions he oversaw as governor of Maryland. Under his leadership, the state tightened gun laws, implemented a progressive tax code and legalized same-sex marriage. He also expanded the state's health care rolls, championed Obamacare and signed a bill raising the state's minimum wage to $10.10 an hour.
Yet O'Malley found himself defending that Maryland record recently when riots broke out in Baltimore over the death of a 25-year-old African-American man under police custody.
The treatment of Freddie Gray, which sparked a national dialogue about police conduct toward racial minorities, drew renewed scrutiny to the controversial zero-tolerance policing strategy that O'Malley advocated for as mayor -- part of an aggressive strategy to crack down on crime.
In an interview with CNN's Jake Tapper last month, O'Malley declared that Baltimore saw a "record reduction in violent crime" under his watch.
There are "probably now 1,000 mostly young, poor African-American men who did not die violent deaths in our city" because of these policies
Martin O'Malley enters 2016 presidential race - CNNPolitics.com