At some point, Earth was unified under one government and by all indications that government was the United States of America. Much of the structure of Earth’s Government is based on the American form of Democratic-Republicanism. Although it is possible that the world peacefully transitioned to this form of government at some point, given the past history of the planet, it seems far more likely that some sort of military conquest resulted in the unification of the planet. The planet later joined the Democratic Order of Planets after its forming at some point and subsequently became an important member of that organization and hosted its headquarters.
Earth’s Government appears to be greatly influenced by the system of governance of the United States. This is manifested in several ways. The three branch system of Government employed by the old United States, (Executive, Legislative, and Judicial) is nearly identical to the system used by the Earth in the 31st century (see below for more details). This is further backed by the (re)election of Richard Nixon, which called into question the stipulation in the Constitution that nobody can serve more than two terms as President (although as a head he lacks a body and thus is immune to this and has been reelected to 3 terms in 3000, 3004, 3008). The Earth Flag, Old Freebie, consisted of the thirteen red and white stripes of the American flag (Which was nicknamed "Old Glory" by WIlliam Driver), but with the stars replaced with an image of the Earth.
The Executive Branch is led by the President of Earth, although there are many other individuals involved in the part of the government. It is responsible for the running of the overall government, as well as enforcing the law.
Although this branch of government has yet to make an appearance in the Futurama series, it seems very likely, considering the extent the rest of the government resembles the classic legislative body (though again, the exact composition of this entity, if it exists, is unclear). This branch would be responsible for passing laws and dealing with appropriating funds for the running of the government.
The judicial branch of Earth consists of at least two levels of courts which deal with a range of different cases. The court system for local and regional districts (although the USA had different levels of courts, it is unknown whether 31st century Earth’s system is similarly split up). An example of such a court is New New York’s Famous Original Ray’s Superior Court, with Judge Ron Whitey presiding.
The Supreme Court, is the highest court on the Planet, the Supreme Court decides high profile cases as well as determining the interpretation of laws (presumably passed by the Legislative branch). A notable development in the court occurs between 3004 and 3009, whereby the votes of female members of the court are only counted as half the value of male justices. However, this genderist law may have been considered unconstitutional after the events of Neutopia Template:See also
The Central Bureaucracy
The exact relationship between the Earth Government and the Central Bureaucracy is unclear, but there seems to be some connection between the entities as the Central Bureaucracy has influential control in Earth’s society.
It appears that any being on Earth who holds citizenship has the right to vote in elections (though being convicted of criminal activity voids this right), including humans of every variation of race, religion, gender, as well as sexuality. It also includes emigrated alien species and robots. Although suffrage has been extended to all native Earthicans, voter apathy has also been continued as the public still doesn’t seem to care for politics. Also of note: while there appears to be many more robots than humans on Earth, robots only made up one third of the total votes in the 3000 election, showing that robots are even less interested in politics than organic beings.