Dianne Feinstein is a liar:
In fact, getting the camel’s nose under the tent, as Ifill puts it, is exactly what they are trying to accomplish. As Olson and Kopel exhaustively document in All the Way Down the Slippery Slope: Gun Prohibition in England and Some Lessons for Civil Liberties in America, the gun banners got Great Britain from complete gun freedom to a complete ban by taking slow, seemingly moderate steps:
Severe enforcement of the rifle and handgun licensing system would not have worked in 1922. Too many gun owners would have been outraged by the rapid move from a free society to one of repressive controls. By initially enforcing the 1920 legislation with moderation, and then with gradually increasing severity, the British government acclimated British gun owners to higher and higher levels of control. . .
The frog-cooking principle helps explain why America’s Handgun Control, Inc. (HCI), and the other anti-gun lobbies are so desperate to pass any kind of gun control, even controls that most observers agree will accomplish very little. By lobbying for the enactment of, for example, the Brady Bill, HCI established the principle of a national gun licensing system. Once a lenient national handgun licensing system was established in 1993, the foundation was laid so that the licensing system can gradually be tightened.
They’re trying the same thing here, but Americans are wise to them, which is why we fight everything. The courts have held that the First Amendment protection for free speech requires “breathing room”, which means that not only must the government not ban free speech, it must not come anywhere near it. The British experience shows that we need “breathing room” for the Second Amendment as well.
UPDATE: A Washington Post editorial from 1994 admitted that the the so-called assault weapon ban served no purpose other than as a stepping stone:
No one should have any illusions about what was accomplished (by the ban). Assault weapons play a part in only a small percentage of crime. The provision is mainly symbolic; its virtue will be if it turns out to be, as hoped, a stepping stone to broader gun control.