A general definition of leadership is that it shows the way for others either by example or by advocacy. Crucially, this definition is sufficiently general that it does not entail being in charge of those who follow.
that it does not entail being in charge of those who follow.
How could this that-clause come out in this sentence? For example, because "so or such" can be followed by that-clause, I know why that-clause appears after so or such. But how could the above sentence have "that-clause"?