President of Earth

The President of Earth was a title held by one person at a time by at least the 26th century. Both Earth and the broader Earth Empire were ruled by this elected figure.

He or she did not, however, have full control over every aspect of the Empire. In purely military matters, the president was unable to overrule the head of the military without the backing of the Earth Senate. Also, the President of Earth had limited control over the affairs of the dominion planets, like Sirius IV: dominions were semi-autonomous and the president had no control over their domestic affairs. (DW: Frontier in Space)

The president led a democracy, and had to submit to periodic election cycles in which various candidates argued their positions in order to win popular approval. Earth Security was a shadowy police organization which could hold troublemakers without trial. In extreme cases, the president had the power to remove political rivals to the Lunar Penal Colony for the rest of their lives. The position thus had elements of democracy and dictatorship about it. (DWN: Doctor Who and the Space War)

In 2540 the president came under great pressure to declare war on the Draconians, especially from General Williams, but was able to maintain peace thanks to the the Third Doctor. (DW: Frontier in Space)

Earth's Presidency was based in the White House in Washington, D.C. during the Orion War of the late 26th century, when Duncan Levinson was President of Earth. (BFC: Scorpius) Upon Levinson's death, Karen Brett took Presidential office. (BFC: Fear) In the year 4041, the current President was still based in the Oval Office of the White House, where he was secretly under the control of the Klytode until the Tenth Doctor freed him. (DWAM: Return of the Klytode)

One President of Earth had daughters who in turn had androids that controlled EarthWorld. (EDA: EarthWorld)