We can see your problem, but consider that as electors it is your responsibility, each and every man jack of you as individuals, to call time on the tendency of The System to silence you. We have held our tongues too long after past massacres, snd now feel that matters have to change: we asked you a while back who would apologise to the parents of the next generation of dead schoolkids, explaining why thye did nothing, and now we can show you tht no explanation is rational: you have no choice now, you must ban those weapons or be equally guilty as the murderer the next time something happens.
Change.org is working in this direction both here in the UK and in the US. The problem with a two-party system is that it makes targetting your representatives an easy technique, if you have the funds: the petition system in the UK is adding a vox populi dynamic, with both parties trying to recruit them, unsuccessfully.