What did Stephen Douglas's theory of popular sovereignty lead to?

It seemed like a reasonable solution to the slavery debate - let the people of each new state vote on whether it would be slave or free.

The flaw in the argument was that the states would be voting one at a time. So every bully-boy in America, from both sides, would descend on one thinly-populated area to commit maximum mayhem.

When it was tried-out, in Kansas, the result was called 'Bleeding Kansas'.