It is merely a theory that explains how free enterprise works. Banks for example, a very important part of the economy, are left out. Some socities do not accept the circular flow model theory. These socities, therefore, choose another economic system other than capitalism. Socialists and communists see the role of the government in a different light than capitalists do.
The United States Constitution states that the Vice President of the United States is the President of the Senate, despite not being a senator, and that the Senate must choose a president pro tempore.
The President of the Senate (who by the Constitution is also the Vice President of the United States) is Joseph Robinette BIDEN (D). The President pro tempore of the Senate is Daniel Ken INOUYE (D-HI). The Senate Majority Leader is Harry Mason REID (D-NV). The Senate Minority Leader is Addison Mitchell McCONNELL (R-KY).