U.S. Attorney Jenny Durkan says the federal government will prosecute more crimes involving guns, so that more of these criminals end up doing federal time. Do you think a federal enforcement effort can make a measurable difference? If so, how: By making more criminals afraid to use guns, or by taking more criminals off the streets? And if you think it could make a difference, how much of an effort and how long?

Years ago I used to hear arguments about "the root causes" of crime being poverty, unemployment, etc., and that fixing those things would lower the crime rate. These days I hear much less confidence in the ability to define root causes and to "fix" them. What do you think about this?