washington u.s. congressional panel next month hold hear violent extremism include threats domestic militants follow white supremacist rally charlottesville virginia turn deadly chairman u.s. house representatives homeland security committee republican michael mccaul announce sept. 12 hear letter panel top democrat bennie thompson committee hold hear year around anniversary sept. 11 2001 attack discuss worldwide threats committee aide say charlottesville protest prompt decision broaden hear include threats domestic militants thompson say move adequate appropriate address request hear threats white supremacists neo-nazi group september 12 hear cover worldwide threats annual hear already schedule prior domestic attack weekend thompson say allow us go depth necessary address far-ranging multifaceted aspects threat pose domestic terrorist threats white supremacist neo-nazi group homeland security committee invite leaders homeland security department federal bureau investigation national counterterrorism center mccaul say must stand together reject racism bigotry prejudice include hateful ideologies promote neo-nazis kkk white supremacy group mccaul write response democrats request hear 32-year-old woman kill saturday charlottesville car plow rival protest white supremacist demonstrators 20-year-old ohio man say harbor nazi sympathies charge murder president donald trump tuesday say side blame violence draw condemnation fellow republicans democrats fail single white nationalists violence prompt u.s. congress discuss militant threats