The Senate might not have any African-American members after the election, when Sen. Roland Burris (D-Ill.), the only sitting black senator, vacates his seat.

Overall, the Senate has never had more than one black member at a time. Burris replaced President Obama in this distinction after filling his Illinois seat following the 2008 election. Before Obama, Carol Moseley Braun, also from Illinois, served from 1993 to 1999.

In total, there have been six black senators since Reconstruction.

The 2010 field has lacked competitive African-American Senate candidates from the start. One exception, Rep. Kendrick Meek (D) in Florida, has consistently polled behind opponents Marco RubioMarco Antonio RubioDemocrats cool on Crist's latest bid for Florida governor Tim Scott sparks buzz in crowded field of White House hopefuls The unflappable Liz Cheney: Why Trump Republicans have struggled to crush her  MORE (R) and Gov. Charlie Crist (I) and is not expected to win on Tuesday.

Meanwhile Burris's seat in Illinois will go to either Republican Rep. Mark KirkMark Steven KirkDuckworth announces reelection bid Brave new world: Why we need a Senate Human Rights Commission  Senate majority battle snags Biden Cabinet hopefuls MORE or Democrat Alexi Giannoulias. Kirk led the polls by 4 points as of Oct. 31.