The only unassailable, filibuster proof majority in American history was between 2009 and 2011, under democrats. A decade after Columbine. What this means is that actual legislation of virtually any sort, could have been passed by them. These would be laws, from Congress, where they are meant to spring forth from, that could not simply be penned over by whomever becomes the next president. If the political goal is proving moral superiority, neither democrats or republicans are doing as well as they seem to think. Also, it is a pathetic, dead-end goal. And if you are blaming Trump (who is a horrible person and president) for these shootings, you are doing so at least in part to alleviate the personal shame of our own responsibility, as a society, for what is happening here.