Political Science

Division of power among different sections of the government is one of the basic principles of the United States Constitution. The constitution separates the power of the state into three branches The Executive branch, the Legislative branch and the Judiciary.

Another aspect to the devolution of power is limits to the powers held by the Federation, power that is delegated to the states.

One of the important powers that are held to be the exclusive power of the Federation is the overall control of the economy of the nation. The power of economic control is held by the Federation, mainly through what are called the Contract Clause and the Commerce Clause of the constitution.
In the Contract Clause states are forbidden from issuing currency
No State shall.... grant letters of marquee and reprisal coin money emit bills of credit (U.S. Constitution. Art. I, Sec. X, Clause I)

The original purpose of this clause was to forbid states from issuing bills of attainder absolving individuals from paying their debts (Levy, Karst,  Mahoney, 1986). However the wider affect of the clause it to grant the Federal government the exclusive control over monetary affairs of the country.
The Commerce Clause grants the Federation, through the Congress, the right to regulate commerce with foreign nations, interstate commerce and commerce with Native American tribes (U.S. Constitution. Art. I, Sec. VIII, Clause III).

This is also an important aspect of the economic power of the Federation, since the states may not enter into financial treaties with any foreign nation or amongst each other without the approval of the Federation.

One of the important aspects of the devolvement of power as set in the constitution is the right of the legislative branch to give advice and consent to the treaties with foreign nations and the appointments to public office made by the President (U.S. Constitution. Art. II, Sec. II).

How this advice and consent works has historically been an issue of contention. Nowadays, the tradition is that the President nominates people to positions such as Supreme Court seats, ambassadorial positions, heads of the armed forces etc. These appointees are then brought before the senate and after some questioning by the members of the senate are approved provided that they have the support of at least three-fifths of the members of the senate in sessions of the senate that are called confirmation hearings (Sachs, 2003).

For treaties with foreign nations, a ratification of at least two-thirds of the members of the senate is required. For these too, the treaty is usually signed by the president first and ratified by the senate later (Sachs, 2003).

In a democracy, devolution of power can work only as long the majority approves of it. It is possible for a highly popular individual to be elected into power and then work through the legislature to concentrate all power within themselves (Levy, Karst,  Mahoney, 1986).

To prevent this from happening, the framers of the constitution have made it very difficult to change the basic structure of the government through amendments in the constitution.

Amendments in the constitution can be proposed by the Congress or by a national convention for proposing amendments to the constitution that is proposed by the legislature of at least two-thirds of the states in the Union (U.S. Constitution. Art. V).

The amendments to the constitution require the approval of the legislatures or ratifying conventions of at least two-thirds of the states in the Union to become parts of the constitution (U.S. Constitution. Art. V).

The alternate of ratification by ratifying convention allows the Federation the option of bypassing the state legislatures in times of need.