We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence,[note 1] promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.
An example of the way courts utilize the Preamble is Ellis v. City of Grand Rapids. Substantively, the case was about eminent domain. The City of Grand Rapids wanted to use eminent domain to force landowners to sell property in the city identified as "blighted", and convey the property to owners that would develop it in ostensibly beneficial ways: in this case, to St. Mary's Hospital, a Catholic organization. This area of substantive constitutional law is governed by the Fifth Amendment, which is understood to require that property acquired via eminent domain must be put to a "public use". In deciding whether the proposed project constituted a "public use", the court pointed to the Preamble's reference to "promot[ing] the general Welfare" as evidence that "[t]he health of the people was in the minds of our forefathers". "[T]he concerted effort for renewal and expansion of hospital and medical care centers, as a part of our nation's system of hospitals, is as a public service and use within the highest meaning of such terms. Surely this is in accord with an objective of the United States Constitution: '* * * promote the general Welfare.'"
"Don't be fooled"
We are not fooled by you. You are a message board troll (a particularly lame one), not a constitutional nor legal scholar by any stretch of the imagination, including your own.
You are forgetting about the Commerce Clause! The Commerce Clause means anything Obama wants it to say while completely ignoring the rest of the Constitution. Chief Justice Roberts will "jump over the broom" to unite in unholy matrimony with any liberal!