NEW : Holder says hearings should n't `` alienate entire communities '' NEW : Congressman pledges : `` I wo n't demonize anyone '' NEW : Rep. Peter King , the chairman of the House Homeland Security Committee , has said Thursday 's hearing is necessary to explore the extent to which al Qaeda is trying to influence and indoctrinate U.S. Muslims , among other things . King says attacks inspired by al Qaeda could have killed thousands .
NEW : Holder says hearings should n't `` alienate entire communities '' NEW : Congressman pledges : `` I wo n't demonize anyone '' NEW : King says attacks inspired by al Qaeda could have killed thousands .