Any people anywhere, being inclined and having the power, have the right to
rise up and shake off the existing government, and form a new one that suits
them better. This is a most valuable, a most sacred right -- a right which
we hope and believe is to liberate the world. Nor is this right confined to
cases in which the whole people of an existing government may choose to
exercise it. Any portion of such people, that can, may revolutionize, and
make their own of so much of the territory as they inhabit. 
 -- Abraham Lincoln [!], January 12, 1848 speech in Congress