Explain how the Constitution augmented national authority.

The Constitution increased national or central power in a
couple of distinct ways.  The fact that the executive branch became powerful or
possessed power under the Constitution was a stark departure from the Articles of
Confederation, which gave little power to the central government.   The fact that the
Constitution specified that the government was to work in the light of a "more perfect
union" helped to build the idea that all states had to work together.  The Supremacy
Clause in the Constitution that stated that "The Constitution is the supreme law of the
land" helped to lend credence to the national government and increase national
authority.  The principle of Federalism and the tenth amendment both helped to construct
a relationship between states and national authority as a working partnership, but one
in which the national structure of government held power over its local counterparts. 
The Constitution's construction of central authority, as being able to respond to issues
such as Shays' Rebellion, with force and with clear mandates for order helped to
increase national authority in a manner that its predecessor, the Articles of
Confederation, could never do.