The General Welfare Clause Is Not A Blank Check

The general welfare clause is not a blank check. I firmly believe it's a preamble to the specific itemized list that follows it.

If the general welfare clause permitted anything as some claim, what would be the point of following it with a detailed list of permissible actions/items?

Congress has not unlimited powers to provide for the general welfare,
but only those specifically enumerated.
-- Thomas Jefferson

If Congress can do whatever in their discretion can be done by money, and will
promote the General Welfare, the Government is no longer a limited one, possessing
enumerated powers, but an indefinite one, subject to particular exceptions.
-- James Madison, letter to Edmund Pendleton, 1792

They are not to do anything they please to provide for the general welfare, but only
to lay taxes for that purpose. To consider the latter phrase not as describing the
purpose of the first, but as giving a distinct and independent power to do any act
they please which may be good for the Union, would render all the preceding and
subsequent enumerations of power completely useless.
-- Thomas Jefferson

With respect to the words general welfare,
I have always regarded them as qualified
by the detail of powers connected with them.
To take them in a literal and unlimited sense would be
a metamorphosis of the Constitution into a character which
there is a host of proofs was not contemplated by its creators.
-- James Madison
(1751-1836), Father of the Constitution for the USA, 4th US President

If Congress can employ money indefinitely to the general welfare, and are the
sole and supreme judges of the general welfare, they may take the care of
religion into their own hands; they may appoint teachers in every State, county
and parish and pay them out of their public treasury; they may take into their
own hands the education of children, establishing in like manner schools
throughout the Union; they may assume the provision of the poor; they may
undertake the regulation of all roads other than post-roads; in short, every
thing, from the highest object of state legislation down to the most minute
object of police, would be thrown under the power of Congress. ... Were the
power of Congress to be established in the latitude contended for, it would
subvert the very foundations, and transmute the very nature of the limited
Government established by the people of America.
-- James Madison
(1751-1836), Father of the Constitution for the USA, 4th US President

Additional links:
Walter E. Williams on the General Welfare Clause