I think it bears repeating again here that very few, if any, 'Liberals' are advocating for banning or outlawing guns (at least handguns, types of assault rifles, or other high powered weapons are a different story), but more advocating for reasonable precautions, such as background checks, waiting periods, etc., none of which interfered with the rights of law abiding citizens to own guns, but which only impose a minor inconvenience when purchasing them. By the way, a majority of NRA members also support such reasonable laws--the NRA itself is badly out of touch with its rank and file members in its policy advocacy, which drives home the point that the NRA doesn't care all that much about its members, it cares about the gun manufacturers that it represents. Their interests, and their interests alone, drive the NRA's extreme positions--extreme by its own members standards.
So, unless you want to call rank and file NRA members all "liberals', this is not a liberal conservative issue, but, in my view, more of a reasonable person vs. fanatic issue, and the fanatics are winning.