When Eli runs into Jackie at the door, and she asks who he is, he facetiously says "the plumber." This is likely a veiled reference to the White House "plumbers," a a covert White House Special Investigations Unit established to stop further leaks of the Pentagon Papers. This parallels Eli's political job.
Chris Noth (Peter Florrick) & Sue-Anne Morrow (Karen Sanborn) also worked together on episode 5.8, Saving Face (2005), of Law & Order: Criminal Intent (2001)] as Mike Logan & Sandra Markham respectively.
Chris Noth (Peter Florrick) & Bruce Altman (Judge Ira Garrett) also worked together on three episodes of Law & Order (1990) as Mike Logan & Harv Beigal/Tom Morrison respectively.
Chris Noth (Peter Florrick) & Jack Gwaltney (Charles Clay III) also worked together on episode 1.8, Poison Ivy (1990), of Law & Order (1990) as Mike Logan & Officer Davis respectively.
Chris Noth (Peter Florrick) & Maury Ginsberg (Opposing lawyer) also worked together on episode 7.12, Contract (2008), of Law & Order: Criminal Intent (2001) as Mike Logan & a screenwriter respectively.