Promote the General Welfare is in the Preamble and Provide is in Article 1 Sec. 8, however this does not give Congress unlimted legislative powers to legislate no matter how much the " living document" views and those who side with Hamilton the matter would like it too. There are literally numerous cases where the Supreme Court has struck down all or part of legislation based on constitutional merits. In fact as I poseted elsewhere, the Supreme Courts view on the matter is quit clear
ButlerCase
T]he [General Welfare] clause confers a power separate and distinct from those later enumerated, is not restricted in meaning by the grant of them, and Congress consequently has a
substantive power to tax and to appropriate, limited only by the requirement that it shall be exercised to provide for the general welfare of the United States. Â… It results that the power of Congress to authorize expenditure of public moneys for public purposes is not limited by the direct grants of legislative power found in the Constitution. Â… But the adoption of the broader construction leaves the power to spend subject to limitations. Â…
[T]he powers of taxation and appropriation extend only to matters of national, as distinguished from local, welfare.
but all Duties, Imposts and Excises shall be uniform throughout the United States.
Same Justice Story commenting on this clause...
It was to cut off all undue preferences of one state over another in the regulation of subjects affecting their common interests. Unless duties, imposts, and excises were uniform, the grossest and most oppressive inequalities, vitally affecting the pursuits and employments of the people of different states, might exist
Taxing and Spending Clause - Wikipedia, the free encyclopedia
There is a reason why it's called the tax and spend clause, and not the compel for general welfare clause.
The General Welfare clause in Article I Section 8
is an introduction to the enumerated powers that follow
and not itself a grant of power.
James Madison, when asked if the "general welfare" clause was a grant of power, replied in 1792, in a letter to Henry Lee,
If not only the means but the objects are unlimited, the parchment [the Constitution] should be thrown into the fire at once.