First on the Hitler nonsense, just stop, the very said thing can be said about republican action over the last few years.
"We must close union offices, confiscate their money and put their leaders in prison. We mush reduce salaries and take away their right to strike" -- Adolf Hitler, May 2, 1933.
Second, even the most conservative judge on the Supreme Court would uphold what Obama has proposed. From DC v Heller via Wiipedia:
(2) 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
Scalia's opinion for the majority provided 2nd Amendment protection for commonly used and popular handguns but not for atypical arms or arms that are used for unlawful purposes such as short-barreled shotguns. Scalia stated: "Whatever the reason, handguns are the most popular weapon chosen by Americans for self-defense in the home, and a complete prohibition of their use is invalid." "We think that Miller's "ordinary military equipment" language must be read in tandem with what comes after: "[O]rdinarily when called for [militia] service [able-bodied] men were expected to appear bearing arms supplied by themselves and of the kind in common use at the time." 307 U. S., at 179." "We therefore read Miller to say only that the Second Amendment does not protect those weapons not typically possessed by law-abiding citizens for lawful purposes, such as short-barreled shotguns." Furthermore, military grade weapons not being the sort of weapons that are possessed at home that would be brought to militia duty are not the sort of lawful weapon conceived of being protected. "It may be objected that if weapons that are most useful in military service - M-16 rifles and the like - may be banned, then the Second Amendment right is completely detached from the prefatory clause. But as we have said, the conception of the militia at the time of the Second Amendment's ratification was the body of all citizens capable of military service, who would bring the sorts of lawful weapons that they possessed at home to militia duty."Therefore, weapons that are most useful in military service - M-16 rifles and weapons like it - are also not provided with 2nd Amendment protection.
Third, Obama is not going to take your guns. He isn't going to take your Handgun, your great grandfathers musket, your 12 gauge, or .22. The only gun laws he messed with in his first term actually decreased regulation (allowing them into National Parks).
Fourth, the NRA is using your fear and paranoia to increase its own membership, as well as increase the sales of firearms. And they are very good at it. This happens after every shooting. You know whatever, I'm not going to tell you what to spend your money on, but the NRA exists to to sell guns, not protect your rights, I would suggest at least thinking about that.