Why does Brutus think that people should care about the form of government?

In the same speech, from "in an ordinary crime" to the end of the speech, danforth lends his words the appearance of logic by his use of

The valve seat performs two functions: it provides a seal for the valve in the combustion chamber, and it provides a cool surface to carry heat away from the valve. most valves use a seating angle.

What was the main aim of the northwest ordinance of 1787