This is a bit peripheral to the OP and the article, but...I don't much understand why people presume so much about political tendencies and gun beliefs.
There is a faction of the left that seems to want a nanny state where dependent people rely on the government to make rules, protect them, and take care of them. But in reality, this describes more of a far left contingent and isn't what I see in most of my liberal friends.
There is a libertarian left who wants individual autonomy and freedom, and respect for civil liberties without autocratic intervention into people's morality or religion. But this group tends to want a bit more law than the libertarian right.
There is an autocratic right who utilizes religion to try to legislate morality. Where the autocratic left want laws in order to "protect the children", the autocratic right want to legislate "god's law."
The libertarian right and left do not seem to be well represented in the GOP or the Dems. Both parties seem to be autocratic and the choices we get left with are where we want our autocracy.
This is all leading up to the fact that I tend to reluctantly pick "the children" over "god", meaning I find the autocracy of the left, less repugnant the religion laden autocracy of the right.
Mostly, I want government to stay out of my business. So, I end up a left-leaning, feminist with libertarian tendencies. In reality, I'm a middle-of-the-road swing voter who votes candidates so perhaps it's unfair for me to carry a "liberal" flag, but if I had to pick, that's where I'd go.
In sum, I don't see the left at odds with guns on any fundamental level. If you believe in the freedom of this country, you may identify as left or right, may vote Dem or Rep, and you may be a fierce proponent of our Bill of Rights.
I hate seeing the assumption or the surprise, that left = gun control proponent. Though there may be overlap there, (from the nanny state left), it's sure not a done deal.
Anyway, you can put me in the feminist, left category of gun toters if you want to.