Text of Article 1, Section 8:
The federal government in general, and the Congress in particular, is only in possession of the power delegated to it (see the 10th Amendment). Meaning, if Congress makes a law, not only may it not conflict with some limitation on Congress’ power (not being a discriminatory law, for example), it must also emanate from some provision in the Constitution that gives Congress its ability to make this sort of law.
The textual powers given to Congress can be found throughout the Constitution. But this section, Article One, Section 8, is the source of many of the most important powers. It is essentially a laundry list of powers delegated to Congress. These “enumerated powers” as they are known, range from the particular (Congress can regulate the value of coins) to the sweeping (Congress can tax), and have been the sources of much contention in the public consciousness and in the halls of the Supreme Court.
One of the most broadly interpreted – and controversial – powers emanates from what is known as the Commerce Clause. This power gives Congress the ability to “regulate commerce…among the several states,” whatever this may mean. The lines delineating what is and is not commerce have been in flux since the ratification of the Constitution itself. Moreover, a cousin to the Commerce Clause is the so-called Dormant Commerce Clause, which is an implied limitation on the states which precludes them from acting in a protectionist manner against the interests of interstate commerce.
Another especially broad and oft-cited power comes from the Taxing and Spending Clause. Congress has the power to “lay and collect Taxes…and provide for the common Defense and general Welfare” of the country using the money it has collected. But the contours and limitations of this power are hotly debated, especially in the modern era.
Underlying each of these powers, is what is known as the Necessary and Proper Clause, which allows Congress to do whatever else is ‘necessary and proper’ to carry out its other responsibilities.
Of course, there are numerous other enumerated powers which stem from this section of the Constitution. Congress, certainly, is authorized to accomplish a great many things.