Seventeenth Amendment (1913)

The Senate of the United States shall be composed of two Senators from each State, elected by the people thereof, for six years; and each Senator shall have one vote. The electors in each State shall have the qualifications requisite for electors of the most numerous branch of the State legislatures.
When vacancies happen in the representation of any State in the Senate, the executive authority of such State shall issue writs of election to fill such vacancies: Provided, That the legislature of any State may empower the executive thereof to make temporary appointments until the people fill the vacancies by election as the legislature may direct.
This amendment shall not be so construed as to affect the election or term of any Senator chosen before it becomes valid as part of the Constitution.

Under Article I, Section 3 of the Constitution, state legislatures were responsible for electing U.S. senators. This system started to experience problems in the mid-19th century with the growth of political parties. By the late 19th century, party disagreements left some states without Senate representation for years. This Seventeenth Amendment changed the system so that senators are elected directly by the people. 

The following diagram illustrates how government representatives are elected and appointed. The blue arrow illustrates the process before the ratification of the 17th Amendment. The green arrow shows the change after the 17th Amendment was ratified. http://craigwwright.files.wordpress.com/2008/11/structure_of_u_s_government.jpg

This Fox news clip claims that the 17th Amendment is unconstitutional because it amended the original constitution. The news reporter feels that the 17th Amendment took away state power and that "states no longer [have] a place at the federal table."