Margaret and Charlie prove to be invaluable allies as C.J. has a rough first day in her new position, made even more difficult by a Russian bearing radioactive gifts and a Defense Secretary's attempts to undermine her; Toby's less than stellar performance in the briefing room makes the search for a new press secretary a top priority, and Josh volunteers Donna to assist him in interviewing potential candidates; faced with a number of vulnerable seats in the upcoming election, Josh attempts to dissuade Matthew Santos from dropping out of another race for the House.

Santos starts up his presidential campaign in New Hampshire, where he immediately disagrees with Josh on campaign philosophy: "No opposition research, no dirt on our opponents." Josh has an uncomfortable reunion with Russell campaign staffer Donna.

The presidential candidates journey to Iowa, where democrats Russell and Santos, and republican Vinick, are all told by their handlers that when they appear before before the corn growers association they must support subsidies for the use of corn-derived ethanol as fuel, regardless of their true feelings.

It's five days before the New Hampshire primary, and Josh is desperately trying to find a "silver bullet" that will get his candidate into the local debate between the two front-runners, Vice President Russell and former Vice President Hoynes. Then, Josh and Santos's disagreements over how to run the campaign come to a head when Santos hires Josh's ex-girlfriend Amy Gardner to help him prepare for the debate he may never be in. And Donna has a memorable encounter with a chicken.

A new candidate for president, Senator Rafferty, has garnered much media attention with a ground-breaking speech about health care. But her words contain interesting echoes of President Bartlet's original health plan, which is known only to White House insiders, and reporter Greg Brock suspects that Rafferty is being secretly supported by the incumbent. Meanwhile, Toby is more than usually morose after the death of his brother. A bill to combat drought conditions in the western U.S. gives C.J. problems, particularly in dealing with lobbyist Clifford Calley. And Charlie tells Kate Harper that a man from his gym asked if she was dating anyone.

Santos is campaigning in California during the last few days before the all-important "Super Tuesday" primary elections, but he is out of money and he trails both Russell and Hoynes in the polls. When even "La Palabra", a Latino voters group, is all set to endorse Hoynes instead of Santos, Josh urges Santos to take a stand on the new bill that denies driver's licenses to illegal immigrants. Meanwhile, Donna tries to figure out why Hoynes suddenly isn't campaigning in California, and advances her position in the Russell campaign by becoming the Vice President's official spokesperson.

Faced with a Democratic party in disarray in the face of the strongest Republican challenger they have ever had, Bartlet asks Leo to take charge of the potentially chaotic Democratic National Convention, while Santos considers a party-unifying vice-presidential offer from front-runner Russell. Meanwhile, the International Space Station is leaking oxygen and a rescue of the three astronauts will be difficult, and Bartlet catches Charlie leaving Zoey's bedroom after a nighttime visit.

At the Democratic National Convention, Russell, Santos and Baker jockey for the 2162 votes that will give one of them the nomination for President, and the opportunity to lose to the apparently unstoppable Vinick in November. Meanwhile, the President must make a decision before it's too late on whether to deploy a secret rescue mission to the space station, and the FBI is asked to determine who leaked the existence of the military shuttle to the press.

As everyone but Josh causes Santos to question his choice of Leo as his running mate, Bartlet's investigation into the dangerous press leak continues. Also C.J. gets interviewed by Babish and Donna approaches Josh for a job.

Santos and Vinick have to deal with press fallout when it looks like the Bartlet White House is not going to continue the investigation into the press leaks.

Margaret is interrogated at a hearing held by the Senate Select Committee on Intelligence; Santos deflects religious questions onto Vinick; Someone gives C.J. intelligence information; a Palestinian leader is assassinated and Bartlet wants to attend the funeral despite security concerns. Also, we learn Margaret's last name.

The White House is trying to cope with the revelation of the identity of the leaker and Babish's questioning of Toby convinces him that he must get his lawyer. Lou persuades Josh to get Santos to clean house with his campaign staff. Kate finally reaches Charles Frost and confronts him about what he told to C.J. and a few other things about his personality in general. The Bartlets hear Ellie's heapful of "good" and "bad" news.

Lou and Santos run into trouble on the road when they try to pick up a family's vote; their child was shot by a Latino police officer. Also, CJ must manage a crisis between China and Kazakhstan.

All eyes are looking forward to the Leo McGarry/Ray Sullivan Vice Presidential debate. Meawhile, Santos is trying not to catch his children's cold and he visits his home in Texas and continues to campaign. Jorge Santos, the Congressman's brother, may cause some problems at a gathering.

After the near-nuclear disaster at the power plant the polls show surprising, or maybe not so surprising, results for both candidates. The Vinick camp gears up for backlash while the Santos camp hopes for cause to celebrate. Meanwhile Bartlet is still trying to keep the situation in Central Asia under control. Relationships in the Santos campaign, the Vinick campaign, and the West Wing all undergo changes and Vinick and Bartlet attempt to deal with different versions of the cold.

Election Day finally arrives, and between analyzing exit polls, and mulling over news reports, a few Santos staff members discover the joys of campaign romance. Meanwhile, C.J. ponders life after the White House; and Annabeth makes a tragic discovery.

Abbey is in New Hamphire with Liz Bartlet-Westin and they are awaiting the results of Doug Westin's campaign for a seat in Congress. Members of both the Santos campaign and the Vinick campaign must decide how to handle a tragedy, as the voters around the country continue to cast their votes for the next President of the United States.

Former series regulars, including Marlee Matlin, Mary-Louise Parker, Tim Matheson, Anna Deavere Smith and Gary Cole, make guest appearances as Bartlet, Santos and their staff members attend a funeral for one of their own. Also, Josh cautions Santos about getting involved in the vote for Speaker of the House.

Former cast member Rob Lowe returns as a senior political official in this episode, which finds Bartlet and his staff making the transition as easy as possible for the president-elect, who discovers some unpleasant realities about his new job. Meanwhile, a stressed-out Josh realizes that he may need to take some time off after he reaches his breaking point.

While Santos is busy trying to select a new vice president, his wife finds her new responsibilities staggering. Meanwhile, Vinick ponders his next move.

C.J. and Will both face uncertain futures as Bartlet and his staffers prepare to leave the White House to make way for the Santos administration.

After seven seasons of the Award-winning drama series, the Bartlet Administration prepares to leave the White House and The West Wing. While Santos and his winning camp are nervously gearing up for the presidential inauguration, current President Bartlet (Martin Sheen), CJ (Allison Janney) and the others fondly look back as they prepare to leave the White House forever.