(I had this written last night but somehow managed to delete it.)
Josh Lyman was White House Deputy Chief of Staff for most of the Bartlet administration until he left to take charge of the Matt Santos campaign for president. Actually that should read "to create out of whole cloth" the Santos campaign given that Santos not only didn't want to run for president but didn't even want to run for Congress. Will Bailey said that Josh had "one of the finest political minds in the Democratic Party." In his role as Deputy Chief of Staff Josh was the tactician - his job was to achieve what Bartlet and Leo McGarry wanted accomplished by whatever means he saw fit. Frequently this meant influencing senators and members of the House, somethig which Josh usually did with a combination of a carrot and a stick. This usually works out but when it doesn't, as in Disaster Relief, it can blow up really bad.
I had a real problem with this one. For all that Josh is a serious character, for me his most memorable scenes were comedic ones, usually involving women and frequently involving his assistant Donatella Moss (for a long time I thought she was saying Donna Teller Moss which confused me). There are scenes like his first meeting with Joey Lucas (Josh is in Sam's sailing gear and doesn't know that Joey is deaf), or his attempt to explain to Donna why she can't get her money back when the government is running a surplus, or this scene, where Josh goes online to interact with the people on his fansite from The U.S. Poet Laureate which if nothing else reinforces the fact that under Sorkin in particular this show was frequently quite funny.
Josh: The Internet people have gone crazy.
Donna: You're kidding.
Josh: They're calling the GAO "General Josh 's Standing Army", and saying I don't understand it's mandate and purpose. They're saying if I could get a review of anything I want, that I should start by reviewing the job of Deputy C.O.S. Then one guy compares me to a poor man's Clark Clifford, and a page and a half of posts, debating whether or not I was mocking Egyptians with the Sanskrit reference.
Donna: I told you they were hysterical.
Josh: I thought you meant they were funny.
Donna: They're not.
Josh: I know they're not! It's "Lord of the Flies" in there.
Donna: Well, who invited you in the first place?
Josh: It's got my name on it. Look, I don't want to hear about it anymore. We got an energy plan in ten minutes. I'm gonna...
C.J.: Oh Josh!
C.J.: The Federal Page of the Washington Post just called Carol to confirm that you're the Josh Lyman who stated on an Internet website that the White House could order a GAO review on anything it wants.
Josh: Without threatening the separation of powers is what I was saying.
C.J.: You posted on a web site?
Josh: I was communicating with the people.
Josh: C.J., it's a... crazy place. It's got this dictatorial leader, who I'm sure wears a muumuu and chain smokes Parliaments.
C.J.: What did you go there for in the first place?
Josh: It's called LemonLyman.com.
C.J.: Let me explain something to you, this is sort of my field. The people on these sites? They're the cast of "One Flew Over the Cuckoo's Nest."
C.J.: The muumuu wearing Parliament smoker? That's Nurse Ratched. When Nurse Ratched is unhappy, the patients are unhappy. You? You're McMurphy. You swoop in there with your card games and your fishing trips...
Josh: I didn't swoop in, I came in exactly the same way everybody else did.
C.J.: Well, now I'm telling you to open the ward room window and climb on out before they give you a pre-frontal lobotomy, and I have to smother you with a pillow.
Josh: You're Chief Brom-
C.J.: I'm Chief Bromden, yes, at this particular moment. I'm assigning an intern from the press office to that web site. They're going to check it every night before they go home. If they discover you've been there, I'm going to shove a motherboard so far up your ass... What?
Josh: Well... technically, I outrank you.
C.J.: So far up your ass!