Democratic Rep. Jesse Jackson, Jr. resigning from Congress

Sorry, Mr. Jackson For anyone following this story, this comes as no surprise:

Congressman Jesse Jackson Jr. is resigning from Congress today, CBS 2 has learned.

He notified staff, supporters and some lawmakers this afternoon, citing health reasons. His resignation letter has been sent to House Speaker John Boehner.

The decision came following two weeks of mounting calls for him to come clean with voters, following revelations that former U.S. Attorney Dan Webb was involved in plea bargaining with authorities who'd been investigating Jackson's alleged misuse of campaign funds.

Jackson, of course, had also disappeared from public view earlier this year and received treatment for an unspecified medical condition that was the subject of many conflicting and sketchy reports. He never addressed the matter publicly, but still won re-election, albeit by the smallest margin of his career. Now, in addition to leaving Congress, jail time looks increasingly likely.

A special election will soon follow this announcement, though in this dark blue district, the Democratic primary is the only race that matters. Some possible candidates include: ex-Rep. Debbie Halvorson, who got trounced by Jackson earlier this year in a comeback attempt; state Sen. Emil Jones III (though his father, the former State Senate president of the same name, was very unpopular); and state Sen. Toi Hutchison, who was Halvorson's old chief of staff when she served in the state Senate. Illinois' 2nd is also heavily black (and the Dem primary electorate even moreso), but if a bunch of African-American politicians were to enter the race and split the vote, that could allow Halvorson, who is white, to sneak through with a plurality.

In any event, many more names are likely to emerge from the woodwork, and as always, we'll be following future developments closely.

12:07 PM PT: Here is Jackson's letter of resignation.