Some high-court sanity at last!

So it seems that 5 out of nine justices on the Supreme Court upheld the 2nd amendment right of the people to keep and bare arms. This is all very well and good and I am glad that it worked out this way. My question is how could 4 out of nine conclude that this was not the case? It says so right in the amendment and yet 4 out of the nine best(?) judges in the country could not plainly see this? I think this says a lot more about the politics of the court than of the legal interpretations of the case at hand.