Political commentators begin to criticize Santos' choice of running mate, but Josh remains sure of Leo as his running mate. The investigation into the leak continues and White House Council Babbish interviews C.J. about the investigation. Meanwhile, Donna approaches Josh for a job.
When the Grand Jury convenes on the military leak investigation, Santos and Vinick are left to deal with the fallout. Vinick deftly handles the issue, but Santos, bound by party loyalty, is forced to take the same stance as the Bartlet administration.
Weeks into the campaign, Vinick decides to begin targeting immigration - an issue that Santos hasn't yet addressed. Santos pulls a stunt which leads to higher approval ratings and throws off the Vinick campaign. Meanwhile, Vinick has a meeting with Charles Frost.
C.J. has to deal with issues by herself when most of the White House staff is subpoenaed to testify in the leak investigation. A Palestinian leader is assassinated and Bartlet, despite major security issues, decides to attend the funeral. Meanwhile, C.J. is given intelligence information, and the public response to Santos' answer to an intelligent design question bothers Josh, though the rest of the staff is unaffected.
As the White House copes with the knowledge of the leak, Babish's questioning leads Toby to call his lawyer. Josh, with the persuasion of Lou, decides that the Santos' campaign must clean house, and is forced to make hard decisions about who out of the young, inexperienced staff should go. Meanwhile, Bartlet and Abbey meet Ellie's fiancée, and Kate confronts Frost about his ambush on C.J.
An attack ad on Santos sponsored by a pro-life organization puts both campaigns in a bind when the focus turns to the candidates' stance on abortion. Donna joins the Santos campaign team, but is hired by Lou, not Josh. Meanwhile, Will takes over Toby's old job and is forced to face the press buzz surrounding the leak investigation.
Santos and Vinick go head-to-head in a live, primetime debate. Two versions, one for the East coast and one for the West coast aired, moderated by Forrest Sawyer and hosted by Ellen Degeneres.
After the boost from the debate, Santos runs into trouble when he visits a Los Angeles community where a young African-American boy was shot and killed by a Latino police officer. Meanwhile, Ellie continues to plan her wedding, and C.J. deals with a crisis between China and Kazakhstan.
On the day of Ellie's wedding, Bartlet must try to help an escalating situation between China and Russia regarding oil all while preparing for his daughter wedding at the White House. Meanwhile, as Election day approaches, the Santos campaign begins to question Josh's leadership, threatening his job.
As the staff prepares for Leo's Vice-Presidential debate, they must deal with Internet criticism that Leo is weak and unfocused. Meanwhile, when Santos stops by his home while on the campaign trail, he and Helen must learn to cope with the new security surrounding their home as well as problems that Jorge Santos, Matt's brother, may cause them.
C.J., while in the middle of the China-Russia crisis, must deal with embarrassing information about a Bartlet all while monitoring the conditions in the Sudan. Meanwhile, Josh goes to Will for help with the campaign, and C.J. and Danny go to dinner together.
With the possibility of a nuclear reactor exploding in California, the presidential hopefuls struggle try to come up with a strategy to deal with the impending disaster while President Bartlet faces the problem as well. Meanwhile, Kate keeps close watch on Russia and China fighting over Kazakhstan.
The candidates are surprised at their poll ratings after a close call at the San Andreo nuclear plant. Meanwhile, Bartlet debates whether or not to send U.S. troops to Central Asia to keep the peace between China and Russia in their continuing battle over Kazakhstan.
As election day nears, the candidates begin to feel the strain of the campaign trail. Despite the lack of sleep and physical ailments, the candidates are forced to make difficult campaign choices. Things take an unexpected turn when Vinick finds an opportunity to hurt the Santos campaign.
Toby is pressured to reveal the source of the shuttle leak; as election day nears, Santos pushes himself to his limit while on the campaign trial.
During the night before Election Day, C.J. is faced with choosing between job offers, Josh stresses over the returns, and Annabeth makes a shocking discovery.
As the polls close and results begin to trickle in, tensions, as well as emotions, fly. Santos and Josh deal with the loss of the Vice Presidential Candidate, and Vinick argues with his campaign team. Meanwhile, the First Lady and Liz Bartlet-Westin eagerly await the results of Doug's campaign for Congress.
In the wake of Leo's death, the current staff, as well as staff members from the past, join President Bartlet at Leo's funeral. Meanwhile, Santos must deal with the loss of his running mate.
The White House is shocked when the President-Elect calls the President of China, taking a different position on foreign policy than that of President Bartlet. Meanwhile, Josh debates who to choose as deputy Chief of Staff.
While Santos debates who to choose as his Vice President, Helen has to deal with her new duties as First Lady and new issues the First Family are facing. Meanwhile, Vinick has to figure out what to do now that the election is over.
With Santos' inauguration nearing and the Bartlet administration preparing to leave the White House, C.J., as well as the other staff members, has to decide what to do with her future. Meanwhile, Andy asks Bartlet to pardon Toby so he won't be faced with jail time, and C.J. and Danny talk about their relationship.
As the Bartlet administration prepares to make their exit, the staff pauses to look back on their past 8 years working in the West Wing. Meanwhile, the incoming Santos administration nervously awaits the inauguration, and then Santos' staff take their new positions and offices in the White House.
Keb' Mo' -- America The Beautiful, Jack's Mannequin
-- Dark Blue, Jeff Buckley
-- Hallelujah, Charles Brown -- I Want to Go Home, Jaci Velasquez -- The Angel Song