a breath of = a decision of?

Context:

The broad foundation upon which our Constitution rests being the people--a breath of theirs having made, as a breath can unmake, change, or modify it--it can be assigned to none of the great divisions of government but to that of democracy. If such is its theory, those who are called upon to administer it must recognize as its leading principle the duty of shaping their measures so as to produce the greatest good to the greatest number. But with these broad admissions, if we would compare the sovereignty acknowledged to exist in the mass of our people with the power claimed by other sovereignties, even by those which have been considered most purely democratic, we shall find a most essential difference.

Read more at the American Presidency Project: www.presidency.ucsb.edu http://www.presidency.ucsb.edu/ws/index.php?pid=25813#ixzz1n79mqEZk