Here is the thing. Keeping guns out of the hands of unsupervised children, criminals, and the mentally ill has virtually 100% approval. "Arming kids for their own protection" is pure strawman. Teaching kids gun safety and how to shoot, so they learn to respect a gun and what it can do? That's popular. Allowing responsible, law abiding adults to possess firearms in areas that are now "gun-free-zones"? Those are popular. Saying all kids should have guns to protect themselves? Not seriously argued by anybody, but a popular talking point among the left.
I mean... you say it's popular, but popular is not policy. Keeping guns out of the hands of the mentioned has near 100% support and approaching 0% support among the GOP elected for implementing laws and regulation that would actually make it
possible (barring a potential exception in doing stuff that would disenfranchise minorities, which as ree noted is one of those areas pro-gun folk seem oddly quite on and the GOP oddly supportive of), and the ATF et al have had their functioning sabotaged and undercut damn substantially. Teaching kids gun safety is popular, but making
sure they have it? Largely untouched, left to third parties (that are of
wildly varying quality) at best, and if there's been any attempts on making it something approaching mandatory or providing federal support or control for quality, availability, etc., particularly from the "pro-gun" crowd, I haven't heard about it. Allowing responsible, law abiding adults to do something that would be near guaranteed to get more people killed, supported, but any means or methods to actually be able to identify that sort of adult? Staunchly opposed and usually hamstrug even if something does get through. As for arming kids... you say it's a left talking point. It's something I've literally heard with regularity. Usually for older kids rather than particularly young, but regular comments that if some high school that got shot up had guns among the kids, that it wouldn't have happened? Yeah. If it's a left talking point there's a hell of a lot of party line R voters around here that'll cheerfully claim they'd shoot someone coming after their guns that have somehow simultaneously become leftists.
Thing you may be missing is that all that shit you just mentioned is only getting basically
any practical support from the pro-control crowd. The other side of that particular argument does just about everything in their power to make any and all of that impossible, unsupported from a legal or governmental angle, or just not even considered for the books.
E: Also grei, an initial possibility may be Jim Webb, a former senator from VA and a near candidate for the 2016 POTUS race. GOP until '06, currently democrat, seems to match most of what you mentioned to a fair degree if not necessarily entirely.