Tune into Fox News any time day or night and you will find frequent comparisons of President Obama to Adolf Hitler. For just like Hitler, Obama wants to disarm the American people so that he can impose a Socialist/Fascist dictatorship. The "Gun Control = Holocaust" meme is so pervasive that it is even invoked by Republican members of Congress. The premise is that Hitler was able to consolidate his power through implementing a gun registry, and then murder six million Jews by confiscating their weapons. It is an article of faith among American gun fetishists that "the first thing Hitler did was round up all the guns."
The myth of Nazi gun control was exploded already in 2004 by Bernard E. Harcourt in his article On Gun Registration, the NRA, Adolf Hitler and the Nazi Gun Laws: Exploding the Gun Culture Wars (pdf warning) published in the Journal of the University of Chicago Law School. It turns out, as Harcourt documents, that the Nazis relaxed many of the gun ownership restrictions that were put in place during the Weimar Republic (as required under the Versailles Treaty). And one could argue that the Nazi Party might not have successfully seized power if gun laws had been strictly enforced during the Weimar Republic, since Hitler had few problems procuring illegal weapons for his paramilitary troops such as the SA.
It is true that after the Novemberpogrom of 1938 the Nazi regime expressly forbade Jews, gypsies, homosexuals and other "undesirables" from owning any weapons (Waffengesetz von 1938), but it is not clear at all that this had any significant effect on the persecution of Jews. And it is patently absurd to point to this as the cause of the Holocaust. The Jews that were detained and then deported after 1938 tended to be older and less-well off; most Jews with any resources left Germany much earlier. The deportation took place with the open or tacit approval and complicity of the vast majority of Germans; any act of armed resistance would have been completely futile. In any case, most of the Jews who perished in in the Nazi death camps were non-Germans and not subject to the Waffengesetz.
But don't expect any rational discussion of history to change the Gun Control = Holocaust hysteria. There is a segment of white males in America who fantasize about using their AR-15 military assault rifles to mow down Obama's gay Muslim storm-troopers who will be coming to a neighborhood near you to take your guns.