Really? That's a difficult case to make.
The original bill of rights did not bind the states, so originally states were clear to regulate arms. The amendment prohibited only the federal government from regulating arms. Knowing this, the qualification about militias makes more sense. Read as "because the states need to be able to do whatever they want in this regard, the federal government is prohibited from meddling in it." One must ask whether the state constitutions originally protected an individual right. Some did, some didn't.
Contrast the language in Pennsylvania, which clearly protects an individual right:
The right of the citizens to bear arms in defence of themselves and the State shall not be questioned.
with the language in Virginia, which clearly didn't:
That a well regulated militia, composed of the body of the people, trained to arms, is the proper, natural, and safe defense of a free state; that standing armies, in time of peace, should be avoided as dangerous to liberty; and that in all cases the military should be under strict subordination to, and governed by, the civil power.
The text "the right to keep and bear arms shall not be infringed" was added to the Virginia constitution in 1971.
Now, its worth noting that the state constitutions also differed on other things, like the right to freedom of religion. This is why I think its the 14th amendment that really created concretely defined individual rights.
Are you talking about the Second Amendment, the Fourteenth Amendment, or the entire Constitution?
2nd. As you can see in the above link, nearly all the state constitutions have been amended over time - in some cases to make them more free and in other cases to make them more constrained. Once the focus becomes the federal amendment, I think it will be subject to tweaking. People will speak of a "constitutional floor."
(You can also clearly see why the right to bear arms would have been at issue in the passage of the 14th, as numerous state constitutions only protected the right of white people to bear arms.)
As far as I'm concerned, the members of the Supreme Court already have their minds made up on politically-charged cases (abortion, weapons, eminent domain, etc.), and they write (spin) their legal opinions in order to make their political views fit the Constitution.
I tend to agree with you there, but I'm not convinced that it doesn't matter what these things say. They consist of principles established and their very establishment tends to ward off direct attacks that might otherwise tempt their opponents. You can come at this with a bunch of bullshit, but you can't ignore it.
RE: Justices extend gun owner rights nationwide.