The preamble to the constitution says: "We the people, of the united states, in order to form a more perfect union, establish justice, ensure domestic tranquility, provide for the common defense, promote the general welfare and secure the blessings of liberty to ourselves and our posterity, do ordain, and establish, this constitution, to the united states of america." I think that the phrase that demonstrates the powers is, " form a more perfect union, establish justice, ensure domestic tranquility, provide for the common defense, promote the general welfare and secure the blessings of liberty" Hope this helps!