Now that Congressman Jackson has resigned his congressional seat it's up to Governor Quinn to call for a special election to replace the congressman, and one plausible scenario would have the special primary in late February with the special general in early April.

The special election will almost certainly be decided during the special primary as the district leans so overwhelmingly Democratic that it is very unlikely that the Democratic nominee would lose the general election. Even the much maligned Jesse Jackson Jr. won re-election in this district with 63% of the vote in 2012 in a year where he was surrounded by a media firestorm and was too ill to campaign in any meaningful way, so it's difficult to envision a plausible scenario where this district is won by anyone other than a Democrat.

The district is geographically large, at least for a Chicago based district, encompassing some of the south side of Chicago, the southeastern part of Cook County, the eastern part of Will County and all of Kankakee County. However the population density of the Democratic Primary electorate leans heavily towards the Cook County portion of the district. Here is the distribution of Democratic Primary voters from 2012, I've separated Cook County into Chicago and Cook Suburbs even though they are both within Cook County:

As you can see about a third of the Democratic Primary vote came from Chicago, about 55% from the Cook County suburbs and then only a little less than 6% from each of Will and Kankakee counties. Here's the same data but broken out by ward/township (I didn't bother breaking out the data for Kankakee since the total is so small):

Vote rich townships like Thornton, Rich and Bloom along with Wards 7 & 9 stand out as possible areas of candidate vote strength. However all of this data is based on the primary electorate in 2012 which featured a reasonably high profile race between incumbent Congressman Jesse Jackson Jr. and former Congresswoman Debbie Halvorson. It is very much uncertain what voters may turn out for a special primary election this winter and predicting what that electorate will look like and who will turn out will be a difficult challenge. That challenge makes polling difficult and also direct mail potentially inefficient and unnecessarily expensive for those who get it wrong. It's likely that the candidate that emerges successful will have an experienced team who were able to accurately capture the likely electorate.

There are a great many rumored candidates, see below for a partial list. Here's a very handy tool I've developed that will allow you to see not only the 2nd Congressional District boundaries in great detail but also the boundaries (past and present) for the districts many of these candidates have represented or run in before. As you can see some candidates only partially shared voters with the voters of IL-02 while others have represented large portions of this district and would benefit from a built in name ID among voters. Here's a partial list of potential candidates, see this piece from the Sun-Times' Mark Brown for more opinionated and in depth analysis:

• Sandi Jackson - wife of the current congressman and both Alderman and Committeeman of the 7th Ward.
• Debbie Halvorson - was elected congresswoman of IL-11 in 2008 and then lost re-election in the general election of 2010, also ran unsuccessfully in the Democratic Primary for IL-02 in 2012. Prior to running for Congress she was the State Senator from the 40th Senate District.
• Robin Kelly - was the Democratic nominee for State Treasurer in 2010 but lost in the general election. She was Chief of Staff to Treasurer Giannoulias during his term and prior to that was the State Representative for the 38th District. She currently works as the COO for Cook County under Toni Preckwinkle. (full disclosure: I formerly worked for Kelly)
• David Miller - was the Democratic nominee for State Comptroller in 2010 but lost in the general election. Prior to that he was the State Representative of the 29th District.
• Todd Stroger - was elected Cook County Board President in 2006 but lost re-election to Toni Preckwinkle in 2010. Prior to that he was the 8th ward Alderman and had been State Representative of the 31st District.
• Darcel Beavers - rival to Sandi Jackson, she ran against Jackson unsuccessfully for Alderman of the 7th Ward in 2007 and 2011.
• Anthony Beale - current Alderman and Committeeman of the 9th Ward.
• Donne Trotter - longtime member of the State Senate currently representing the 17th District and having represented the 16th District in the 90's prior to redistricting. He also ran unsuccessfully for IL-01 in 2000 against Bobby Rush and Barack Obama.
• Toi Hutchinson - current State Senator of the 40th District, she succeeded Debbie Halvorson in that role when Halvorson left to run for Congress.
• Will Burns - current Alderman of the 4th Ward and former State Representative for the 26th District.
• Napoleon Harris - recently elected to his first term as State Senator from the 15th District.
• Mel Reynolds - was formerly the Congressman in IL-01 in the mid-1990s and resigned his seat after a criminal conviction.
• Robert Shaw - He and twin brother Bill were once rivals of Jackson. He is a former 9th Ward Alderman and former Cook County Board of Review Commissioner. He also ran unsuccessfully for State Representative from the 29th District and for Village President of South Holland.
• Sam Adam Jr. - high profile attorney who defended both R. Kelly and former Governor Rod Blagojevich.
• Scott Smith - because #WhyNotScott2012

All of this district lies within the Chicago media market so it seems that broadcast television advertising for this race will probably be prohibitively expensive unless some candidate(s) really excel at fundraising. The more plausible scenario is that the most flush candidates could end up on cable television. Here's the Comcast coverage map for their regional cable markets in the Chicagoland area. Unfortunately their map is rather small and difficult to read but you can see that a candidate in this district would only need to buy just a few regions.