The gun sanctuary going on within the state seems to be helping Trump.
Like how "post-birth abortion", Fairfax's rape scandals, and Northam's blackface were supposed to help the GOP hold the state legislature?
That was 7 months before the election. The gun stuff is likely helping Trump's numbers for the time being.
I find it hard to imagine that anyone who's motivated by gun rights hasn't consistently been answering polls positively for Trump for many years.
It's possible there are a bunch of otherwise apolitical gun owners who get motivated to answer polls and go vote when the government starts going after them. A lot of people only care about politics when they're angry.