The attitude that everyone has a right to carry a gun encapsulates the perception of the right-wing - that they are the only ones intelligent and compassionate enough to arm themselves against the immoral filth they are obliged to share the planet with (anyone who is not right-wing).
It's constant rxposure as a ludicrous and dangerous obsession makes not a single dent in this perception, and for the foreeable future, no Democratic candidate will step up without membership of the NRA - it's support is too valuable to lose.