Eric Liu : A man was killed because he went to school in Marysville , Washington , today . Liu : Steady stream of shootings makes them virtually normal . Is this ` ` American exceptionalism '' ? It 's contagious here . Some activists wrongly say background checks wo n't help , he says . Liu : We the people must set tone , standards , with standards , standards . It 's our responsibility .
Eric Liu : A child was killed because he went to school in Marysville , Washington , today . Liu : Steady stream of shootings makes them virtually normal . Is this `` American exceptionalism '' ? It 's contagious epidemic . Gun activists wrongly say background checks wo n't help , he says . Liu : We the people must set tone , standards , with laws , norms . It 's our responsibility .