I also enjoy the "private citizens aren't funding enough research" argument.
Who said anything about private citizens?
The point being, there are endowments and foundations all over the country that are pumping millions upon millions of dollars into the research coffers of research universities. But if you want to believe that having one of those myriad of entities contribute money to research gun violence (knowing full well many fund all kinds of research on social issues all the time) is just a bridge too rough ridin' far, then knock yourself out.
Hey, we've got a real problem with gun violence. Welp, the political situation in Washington isn't conducive to get funding appropriated through federal government channels right now. Well, okay then (insert multi-million dollar endowment/foundation/state agency name here) should just keep funding research on (insert inane extramural research funding project here).