Senate Candidate 5 in the Blago complaint would seem to be in a bit of hot water, since it appears from the tapes that he or she offered Blago something in return for the appointment. (Whether that something was actual money or a promise of future fundraising help isn't entirely clear.) So who's Senate Candidate 5?
Marc Ambinder speculates that it's Jesse Jackson Junior, given the timing of a meeting he had with Blago. But that doesn't seem right to me, since it's also clear from the complaint that Blago believed Obama was opposed to Candidate 5. I can't think of any reason why Obama would oppose Jesse Junior moving over to the Senate. As I reported for the print mag early this year, Obama's relationship with Jesse Senior may be fraught, but he's actually fairly close to Jesse Junior. And, presumably, their relationship grew stronger over the course of the campaign, during which Jesse Junior did yeoman's work for Obama, the least of which was slapping down his dad when he did something against Obama's interests.
The Smoking Gun, meanwhile, says that Candidate 5 is Emil Jones. Obama's relationship with Jones (who, btw, is a sworn enemy of Jesse Junior's) is much, much more complex. Yes, Obama famously cultivated Jones as his political godfather in the State Senate, but that's always seemed like one of those relationships that Obama was happy to leave behind in Springfield. Given some of the baggage that comes with Jones's old-school, machine ways--a number of his family members are on the public payroll, and he's worked hard to make sure his son inherits his legislative seat--I could see how Obama might not want Jones in Washington. What's more, Brad Plumer calls my attention to this post from the Capitol Fax blog, which points out that Jones was mentioned by Sun-Times columnist Michael Sneed a few days after Blago discussed leaking Candidate 5's name, and that Jones has a huge war chest, so it wouldn't be hard for him to come up with $500k.