The gun control issue is to the left what the anti-abortion issue is to the right -- something they believe strongly in but can't possibly win and will cost them a shitton of votes.
Best to talk about it from time to time, but not seriously go after it. Anything else inevitably leaves the party in question gasping from the self-inflicted sucking chest wound...
"I love signature blocks on the Internet. I get to put whatever the hell I want in quotes, pick a pretend author, and bang, it's like he really said it." George Washington