Wow. Some people want a citation for everything...
A well regulated militia being necessary to the security of a free State, the right of the People to keep and bear arms shall not be infringed.
I'm not sure how one can interpret "shall not be infringed" as anything but an absolutely protected right.
To any who doubt this interpretation lets look at what the people who wrote it and fought for it think it says:
Patrick Henry: "The great objective is that every man be armed. . . . Everyone who is able may have a gun."
Alexander Hamilton: "The best we can hope for concerning the people at large is that they be properly armed."
Richard Henry Lee: "To preserve liberty, it is essential that the whole body of the people always possess arms, and be taught alike, especially when young, how to use them."
"The bearing of arms is the essential medium through which the individual asserts both his social power and his participation in politics as a responsible moral being..."-- J.G.A. Pocock, describing the beliefs of the founders of the U.S.
last but MOST certainly not least:
Militias, when properly formed, are in fact the people themselves and include all men capable of bearing arms. [...] To preserve liberty it is essential that the whole body of the people always possess arms and be taught alike, especially when young, how to use them. -- Senator Richard Henry Lee, 1788, on "militia" in the 2nd Amendment
I have yet to see where there is any indication from the authors of the second amendment that the government should be able to restrict the bearing of arms to only some people. In fact such an idea goes counter to amending the constitution to specifically prevent such an act.