But from the perspective of gun owners a collective/state right isn't comparable to an individual right.

Decades ago the ACLU was quite anti-gun. The only reason they got roped into the gun debate (something of a pointless distraction for them) is because of their work with minority communities, their work in helping them deal with the consequences of increasing violent crime during the 1970s and 1980s, and in particular their help in strategizing responses to state and federal laws that they thought were causative or contributive factors of that crime. The ACLU began to believe that equality couldn't be promoted merely by defending the existing panoply of liberties; that to defend civil liberties you had to arm communities with new legal tools to fight what were perceived as biased and oppressive behavior maintained in the guise of equality and liberty. (Just like the original function of the states' rights debate was to protect slavery by appeal to notions of liberty.) And part of that biased behavior was state governments ignoring the plight of some black communities wrt to gun regulation. (As you alluded to, the the prejudice is laid bare by the fact that many of same people and institutions that are today rabidly anti-gun regulation were previously very much pro-gun regulation at the height of and in direct response to the Black Panthers and black power movements, and in particular the movements for them to become armed.)

From the the ACLU's perspective, smart gun regulations could help reduce crime without imposing any undue constraints on legitimate uses of guns. The ACLU and their supporters' notions of legitimate use are clearly in opposition to that of many gun rights proponents--at least the vocal ones who managed to define the debate.

So early on the ACLU provided assistance to communities and legislators writing laws which restricted gun use. And they weren't doing it out of concern about the breadth of those laws. Rather they did so to try to make them as broad as legally and politically possible. It would be sort of like the ACLU not only defending the KKK in a free speech law suit, but helping them write their propaganda. The former defends a principle, the latter is difficult to defend by saying you're just helping them to stay within the bounds of the law.

After the conservative movement gained steamed during the 1980s and 1990s, and after it thoroughly internalized the values and legal reasoning of the rabidly pro-gun rights movement, the ACLU began to see the writing on the wall. It also helped that there always existed conflict internally about their choice to take an official legal stance and to inject itself into the debate at the cost of considerable political capital on other issues. So the past 10 or so years has seen an unwinding of the ACLUs stance and remediation of the trouble it has caused them. That unwinding includes cooperation with the NRA on blocking some federal regulations. It was a very strategic assistance, though perhaps I'm being overly cynical. But from what little I've read internally it created some serious discord because a large contingent of support inside and outside the ACLU comes from the social justice movement, for which gun regulation is a huge issue.

In the next few years don't be surprised if they just silently move away from the issue altogether. I doubt they'll ever affirm an individual right, but they don't have to affirm it. The whole issue was always a distraction from more pressing and important work. Gun violence is a real problem, but it's not something the ACLU is well-situated in any shape or form to help deal with. Better to stop antagonizing guns rights activists, especially when it feeds political divisiveness at at moment when they need all the cooperation they can find fighting for voting rights. And the focus on voting will rightly serve as a distraction for the powerful interests that kept the ACLU in the gun debate for so long.

Plus, the debate is largely over. The law of the land is that gun rights are an individual right under the Federal constitution. End of story. I may disagree with their historical reasoning and some of their legal justification, but I accept that their decision provided finality to both the legal and and political debate. There are alot of unanswered questions, but I don't think they'll be at all consequential.

And for the record, I'm not anti-gun. I'm not afraid of guns. I've shot plenty of guns, including machine guns. I'm comfortable around guns. I'd like to see more open carry and less concealed carry. IMO too many politically left-leaning people have an irrational fear of guns. And while I don't deny that gun regulation could and arguably has limited crime in some countries, I don't think it would be particularly effective nor viable in the U.S. Our gun culture is too strong to make it politically viable, and our society is too violent (criminals and police) for it to really have any effect on street level violence. More regulation won't make the violence go away. What will almost certainly make it go away is less regulation of drugs. I'm not pro-drug, either, but I'll take stepping over more passed out heroin users on the streets than having to worry about dodging bullets. I'd prefer neither, but you can't have everything.