I think 4-5 years is ambitious because this isn't a social equality issue like gay marriage was, plus it's a constitutional protection. Buuuuut, we have had assault weapons bans, there are gunshow loopholes that can reasonably and pragmatically be closed, as well as a host of other minor legislation. With gay marriage, I got the sense even as it was getting shut down by state referendum momentum was actually building against that and the referendums were fueled by a desperate fear on the right while the tide was turning beneath their feet. I'm looking for that current here, but I have to say I'm coming up a bit short. That being said, I'm not going to stop being politically engaged on the issue...but it's true that I'm pretty pessimistic at the moment.