Why can't we? The American Founders literally wanted us to take up arms and kill people who violated our essential liberties. You can read this in their own books and papers. They were extremely clear about this... it isn't even up for debate, unless of course you're talking to a moron that's never actually read Jefferson, Washington, Madison, etc.
If we reach a point where we can't even restate what our Founders said, we're already in our twilight as any kind of civilized liberal society.
Now we can argue about what constitutes an "essential liberty". I'm not sure I'd put, "Heated seats in my BMW" in that category.
