From the Heller decision authored by conservative Supreme Court Justice Antonin Scalia:
Like most rights, the Second Amendment right is not unlimited. It is not a right to keep and carry any weapon whatsoever in any manner whatsoever and for whatever purpose: For example, concealed weapons prohibitions have been upheld under the Amendment or state analogues. The Court’s opinion should not be taken to cast doubt on longstanding prohibitions on the possession of firearms by felons and the mentally ill, or laws forbidding the carrying of firearms in sensitive places such as schools and government buildings, or laws imposing conditions and qualifications on the commercial sale of arms. Miller’s holding that the sorts of weapons protected are those “in common use at the time” finds support in the historical tradition of prohibiting the carrying of dangerous and unusual weapons.
From the amicus curiae (friend of the court) brief filed by the U.S. Department of Justice:
The court of appeals correctly held that the Second Amendment protects an individual right to possess firearms unrelated to militia operations. By its plain text, the Second Amendment secures a "right," a term that the Constitution consistently uses to refer to indi vidual freedoms rather than state prerogatives. The text also makes clear that the right is not limited to members of a select body (like today's National Guard) but extends to "the people" generally.... Like other provisions of the Constitution that secure individual rights, the Second Amendment's protection of individual rights does not render all laws limiting gun ownership auto matically invalid. To the contrary, the Second Amendment, properly construed, allows for reasonable regula tion of firearms, must be interpreted in light of context and history, and is subject to important exceptions, such as the rule that convicted felons may be denied firearms because those persons have never been understood to be within the Amendment's protections. Nothing in the Second Amendment properly understood-and certainly no principle necessary to decide this case-calls for in validation of the numerous federal laws regulating fire arms..
From Senator Barack Obama's statement on the Heller decision:
I have always believed that the Second Amendment protects the right of individuals to bear arms, but I also identify with the need for crime-ravaged communities to save their children from the violence that plagues our streets through common-sense, effective safety measures. The Supreme Court has now endorsed that view, and while it ruled that the D.C. gun ban went too far, Justice Scalia himself acknowledged that this right is not absolute and subject to reasonable regulations enacted by local communities to keep their streets safe. Today's ruling, the first clear statement on this issue in 127 years, will provide much-needed guidance to local jurisdictions across the country. As President, I will uphold the constitutional rights of law-abiding gun-owners, hunters, and sportsmen. I know that what works in Chicago may not work in Cheyenne. We can work together to enact common-sense laws, like closing the gun show loophole and improving our background check system, so that guns do not fall into the hands of terrorists or criminals. Today's decision reinforces that if we act responsibly, we can both protect the constitutional right to bear arms and keep our communities and our children safe..