Illinois is the fifth-largest state in the United States, and is usually a reliably Democratic state, including the city of Chicago.
At the 2010 election, the seat up for election is a Democratic seat previously held by President Barack Obama. The seat is currently held by Roland Burris, who was appointed to the seat in December 2008.
Both Illinois seats have been dominated by Democrats in recent decades, with the Republicans only winning a Senate seat once since 1980.
The seat now held by Burris was won off the Republicans at a special election in 1970 by Adlai Stevenson III, son of the former presidential candidate and grandson of the former Vice President. Stevenson was re-elected in 1974 and retired in 1980. The seat was won in 1980 and 1986 by Alan Dixon (D). In 1992, Dixon lost the Democratic primary to Carol Moseley Braun, who went on to win the seat. Moseley Braun was one of only two African Americans to win election to the Senate in the 20th century.
Illinois’ other Senate seat was won by Republican Charles Percy at the 1966, 1972 and 1978 elections, before he was defeated by Democratic candidate Paul Simon in 1984. Simon won re-election in 1990, before retiring at the 1996 election. The seat was won in 1996 by Congressman Dick Durbin (D), who won re-election in 2002 and 2008.
Moseley Braun only served for one term, losing in 1998 to Republican candidate Peter Fitzgerald. Fitzgerald didn’t stand in the 2004 election. The Democrats selected Illinois State Senator Barack Obama. The Republicans originally selected Jack Ryan, but a scandal saw him withdraw, and he was replaced by Alan Keyes, a Republican figure who had never won elected office and had never lived in Illinois. Obama won the race with almost 70% of the vote.
The 2004 campaign rose the profile of Obama, who was elected President in 2008. Following his election, he resigned from his Senate seat. The Governor of Illinois, Rod Blagojevich (D), was responsible for appointing a temporary replacement for Obama for the final two years of his Senate term. Blagojevich was taped discussing how he would give the Senate seat to whoever gave him personal benefit, and made embarrassing comments about his attitude to appointing a US Senator. After he was arrested by federal officials, most serious contenders stood back from consideration for the seat, and he appointed Roland Burris, a less prominent figure in Illinois politics.
Burris has had a difficult period as a US senator, facing corruption allegations and extremely low poll ratings.
The Democratic primary this year was won by State Treasurer Alexi Giannoulias. The Republican primary was won by Congressman Mark Kirk.
Polling for the general election is very even, with Kirk and Giannoulias both winning a number of recent polls, never by large margins. Giannoulias led in most polls up to March 2010, but from April to June most polls showed Kirk in front by a slim margin. Since July, polling figures have been mixed.