It's working somewhat in colleges. See:
https://www.chronicle.com/article/Top-Official-at-St-Thomas-U/242823
The president of St. Thomas University gave its chief financial officer an ultimatum on Tuesday: Cut ties with a gun manufacturer or resign.
I wouldn't be surprised if social media presence that is gun positive will entire into hiring and promotion decisions in industry, government, education, etc.
To Tom's point, is this latest horror enough to actually move public opinion. It may not be the case that the country would accept total gun bans but banning the semi auto,military appearance guns and the higher capacity magazines can certainly be sold to those not familiar with the issues.
When studies in the past asked about gun control and got a majority of positive responses, deeper analyses demonstrated that most of the country felt supportive of gun ownership by law abiding citizens, and supported controls to keep the guns out of bad actors hands. That's why universal background checks are supported by many. Good people will pass.
Also, the need for EBRs is not seen by many outside the gun choir AND by quite a few inside it. They are not needed for average self-defense (Is 5 enough?). The defense against tyranny is not high in the minds of average folks. Unfortunately, the gun choir defense by major organizations of the defense against tyranny is focused on ranting about socialism. That does not sell outside of niche audience. It might raise money from the niche but loses the war.
Saying that you need the RKBA to prevent your kindergarten teacher from turning your kid into a socialist - isn't going to stand up against a moral panic of continuing rampages.
I'll control my own guns, thank you. Is that a rousing message to compete against images of horror?
I will get flack for not blindly pledging allegiance to leadership. Pledging allegiance to leadership is demanded by both parties. Ignore the sins and incompetence of the leaders! Has that worked out well?