Question: Information:  - Illinois is a state in the midwestern region of the United States, achieving statehood in 1818. It is the 5th most populous state and 25th largest state in terms of land area, and is often noted as a microcosm of the entire country. The word "Illinois" comes from the Algonquin word for "tribe of superior men". With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal, timber, and petroleum in the south, Illinois has a diverse economic base and is a major transportation hub. The Port of Chicago connects the state to other global ports from the Great Lakes, via the Saint Lawrence Seaway, to the Atlantic Ocean, as well as the Great Lakes to the Mississippi River, via the Illinois River. For decades, O'Hare International Airport has been ranked as one of the world's busiest airports. Illinois has long had a reputation as a bellwether both in social and cultural terms and politics.  - The Democratic National Convention (DNC) is a series of presidential nominating conventions held every four years since 1832 by the United States Democratic Party. They have been administered by the Democratic National Committee since the 1852 national convention. The primary goal of the Democratic National Convention is to nominate and confirm a candidate for president and vice president, adopt a comprehensive party platform and unify the party. Pledged delegates from all fifty U.S. states and from American dependencies and territories such as Puerto Rico and the Virgin Islands, and superdelegates which are unpledged delegates representing the Democratic establishment, attend the convention and cast their votes to choose the Party's presidential candidate. Like the Republican National Convention, the Democratic National Convention marks the formal end of the primary election period and the start of the general election season.  - The Atlantic Ocean is the second largest of the world's oceans with a total area of about . It covers approximately 20 percent of the Earth's surface and about 29 percent of its water surface area. It separates the "Old World" from the "New World".  - In American politics, a "superdelegate" is an unpledged delegate to the Democratic National Convention who is seated automatically and chooses for themselves for whom they vote. These Democratic Party superdelegates (who make up just under 15% of all convention delegates) include elected officials and party activists and officials. Democratic superdelegates are free to support any candidate for the presidential nomination. This contrasts with convention "pledged" delegates who are selected based on the party primaries and caucuses in each U.S. state, in which voters choose among candidates for the party's presidential nomination. Moreover, superdelegates are permitted to participate in the primary elections as regular voters.  - Barack Hussein Obama II (; born August 4, 1961) is an American politician who served as the 44th President of the United States from 2009 to 2017. He was the first African American to serve as president, as well as the first born outside the contiguous United States. He previously served in the U.S. Senate representing Illinois from 2005 to 2008, and in the Illinois State Senate from 1997 to 2004.  - A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases a river flows into the ground and becomes dry at the end of its course without reaching another body of water. Small rivers can be referred to using names such as stream, creek, brook, rivulet, and rill. There are no official definitions for the generic term river as applied to geographic features, although in some countries or communities a stream is defined by its size. Many names for small rivers are specific to geographic location; examples are "run" in some parts of the United States, "burn" in Scotland and northeast England, and "beck" in northern England. Sometimes a river is defined as being larger than a creek, but not always: the language is vague.  - The President of the United States (POTUS) is the elected head of state and head of government of the United States. The president directs the executive branch of the federal government and is the commander-in-chief of the United States Armed Forces.  - The Chesapeake Bay is an estuary lying inland from the Atlantic Ocean, and surrounded by the North American mainland to the west, and the Delmarva Peninsula to the east. It is the largest such body in the contiguous United States. The northern bay is within Maryland, the southern portion within Virginia, and is a very important feature for the ecology and economy of those two states, as well as others. More than 150 major rivers and streams flow into the bay's drainage basin, which covers parts of six states (New York, Pennsylvania, Delaware, Maryland, Virginia and West Virginia) plus all of the District of Columbia.  - The contiguous United States consists of the 48 adjoining U.S. states plus Washington, D.C. (federal district), on the continent of North America. The term excludes the non-contiguous states of Alaska and Hawaii and all off-shore United States territories and possessions, which include American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the U.S. Virgin Islands.  - The District of Columbia Democratic Presidential Primary took place on February 12 , 2008 , nicknamed the `` Potomac Primary '' because Maryland and Virginia , which border the Potomac River , also held Democratic primaries that day . Fifteen delegates were up for grabs in the District of Columbia Democratic Primary , including 10 delegates from the District of Columbia 's municipal subdivisions ( five delegates for Wards 1 - 4 , and five delegates for Wards 5 - 8 ) . An additional five delegates were awarded to the at - large winner , Barack Obama . These 15 delegates represented the District of Columbia at the Democratic National Convention in Denver , Colorado . A total of 24 unpledged delegates , known as superdelegates , also attended the convention and cast their votes as well . Barack Obama received the endorsements of Mayor Adrian Fenty and former Mayor Marion Barry ( both African Americans ) , while he and Hillary Clinton were both endorsed by various members on the District of Columbia City Council . Barack Obama won the District of Columbia , as he did the other Potomac contests that day . He earned 12 pledged delegates to Clinton 's 3 .  - The Potomac River is located along the mid-Atlantic Ocean coast of the United States and flows into the Chesapeake Bay. The river (main stem and North Branch) is approximately long, with a drainage area of about 14,700 square miles (38,000 km²). In terms of area, this makes the Potomac River the fourth largest river along the Atlantic coast of the United States and the 21st largest in the United States. Over 5 million people live within the Potomac watershed.    Given the information, choose the subject and object entities that have the relation of 'instance of'.
Answer:
district of columbia democratic primary , election