Apologies for a late reply. You are entirely correct, of course. But that support is subject to manipulation in the media and tends to fall rapidly during hysteria campaigns, the pattern seen in Great Britain, New Zealand, Australia, and Canada. And an activist Democratic administration with a majority of both Houses will most certainly put gun control firmly back on the public agenda with strident support from sympathatic urban media.
It isn't a trend, it's a warning sign, something to watch for. McGee wrote a couple of novels around it.
Interesting times. It would be hard to rule out almost anything going forward.