Shortcomings in mental health treatment, weak laws and a reluctance to threaten personal liberties can derail even concerted attempts to thwart mass shootings.
The deadliest mass shooting of the year will present the president with the familiar ritual of comforting grieving families. He will likely also press his case for gun control.
A state ban on assault weapons? Expanded concealed-carry restrictions? Tighter mental health laws? As Maine grieves, it weighs a roiling debate over gun laws.