One reason that I don't think we are going to see a resolution on this issue is the following:
Politics is now all about extremists and no longer around moderates.
I, for one, would not worry about that. That looks like a blog post, not an ostensibly objective news article.
I reviewed all of the recent articles by the author and he is not at all subtle about being a Left-leaning Democrat, so his political bias makes his essay suspect to begin with.
The conclusion of the study referred to in the article depends entirely on the subjective application of "moderate" or "not moderate" to a variety of political positions. Since we do not know how members' positions on issues were determined or how positions are defined in terms of "moderate" or "not moderate" we do not know anything logically sound about the study.
If I asked a Conservative Republican I am sure he would have no trouble finding a large number of Liberal Democrat "extremists" in the House. It is not surprising that a Liberal Democrat has no trouble defining, and then finding, a large number of Republican "extremists" in the House.
Both parties certainly have extremists. But one side tagging the other side with self-defined labels is not, to me, a fruitful way forward toward compromise and progress on the issues of the day.
As far as Second Amendment issues go, now that we have established that the Second Amendment guarantees an individual right, we can turn to policy ideas which are, in my opinion, Constitutional. These include:
1) background checks at gun shows just like the background checks federally registered firearms dealers have to perform; and
2) requiring people who want to purchase a firearm to pass a written test and a live-fire range proficiency test.
Of course these policies do not deal with mental health regulations and the critical issue of requiring hospitals/doctors/mental health officials to notify local police or the federal background check database of people who have experienced serious mental health issues or attempted suicide (like the recent Oregon school shooter).
Finally, I believe that a ban on semi-automatic firearms is unconstitutional.