Toby Ziegler

Before joining the Bartlet presidential campaign, Toby was a professional political operative who worked for various campaigns, including New York City Council seats, Bronx Borough President and U.S. House and Senate races. However, he had never been on a winning campaign before Bartlet's 1998 presidential bid.[19] He says that he backs the candidates who should win, rather than those who will win, and is unapologetic about his low winning record.[20]

Once in the White House, Toby is rewarded for his work on the campaign, with Bartlet naming him Communications Director and senior domestic policy advisor.[8] Later, it is revealed that Toby was not the president's first choice for the job, although Bartlet confides that he is grateful his first choice turned it down.[21] Of all the senior staffers, Toby is the most prone to clash with the President, being unafraid to challenge his judgment and question his actions when he feels Bartlet is not acting in accordance with his true morality.

When Will Bailey leaves the president's staff to work for the vice president, Toby interprets the move as a betrayal and develops an antagonistic attitude toward Will that never is truly fixed (they simply go from being constantly at odds to having little or nothing to do with each other, though Will is shocked and left near tears when a devastated C.J. tells him about the shuttle leak and installs him as the new Director of Communications). Similarly, when Josh leaves the White House to run a presidential campaign for Matt Santos, Toby views this as a betrayal and is extremely hostile to Josh until long after. His reaction is eventually explained by the revelation that his brother David, recently diagnosed with terminal cancer, committed suicide rather than live what time he had left: "He could have had years. But instead, he just dropped everything and walked away." Toby feels "walking away" is what Josh has also done.[22] Josh later (successfully) moves to keep their friendship alive, and Toby keeps advising Josh as he tries to get Santos elected president.

Toby's oldest friend in the White House is C.J. Cregg, whom he met during an earlier campaign[23] and whom he personally recruited for the position of Press Secretary.[24] When Toby is fired in Bartlet's final year for leaking state secrets, their close relationship is hit hard and neither reconcile until the penultimate episode of the series and Toby's final scene.

Toby accomplishes much in his tenure as Communications Director, including writing both of Bartlet's inaugural addresses as well as his State of the Union addresses. His most notable accomplishment is "fixing" Social Security during the fifth season of the show, the sixth year of the Bartlet administration. He thinks of it early one morning, almost resigns after it is leaked by the senator who he is persuading to break with partisan politics, but then fixes it with the help of Josh Lyman. After C.J. Cregg's promotion from Press Secretary to White House Chief of Staff in early season six, he also serves as the de facto White House Press Secretary in addition to his role as Communications Director. Toby initially has trouble facing the press in the new role and makes several gaffes, but learns to perform well with the help of new Deputy Press Secretary Annabeth Schott.

In the episode "Things Fall Apart," the International Space Station develops a critical oxygen leak. With no civilian shuttles available to perform a rescue mission in time, a three-person crew finds itself trapped aboard the ISS. While the president contemplates rescue options, C.J. becomes aware of the possibility that a secret military space shuttle could be prepared in time to rescue the crew. However, this would involve revealing the shuttle's existence, particularly as one of the ISS crew is a Russian military officer. C.J. shares her speculation with several senior White House staff, including Toby. The information is leaked to Greg Brock, a reporter for The New York Times, which triggers a full-scale investigation.

In the episode "Mr. Frost", Toby admits to C.J. that he leaked the classified information, which estranges the two. He knew that if the military shuttle's existence became public knowledge, the public would demand the safe return of the astronauts, which is what ultimately occurred. White House Counsel Oliver Babish debriefs Toby until his lawyer ends the interview. Toby reveals that he discussed the possible existence of the shuttle with C.J., but does not state that C.J. initiated the conversation. Toby offers his resignation to Bartlet, but Bartlet does not accept the resignation because he must dismiss Toby "for cause". Babish waits with Toby before he is escorted out of the White House, saying that someone should at least thank Toby for his years of service and wait with him to soften the blow.

Toby attends Leo McGarry's funeral, but sits in the back of the church to avoid press coverage. He is similarly unable to attend Leo's burial at Arlington National Cemetery because of the press circus his attendance would cause. Later C.J. is at an impasse about what to do after the administration's time ends and visits Toby. The two have a heartfelt reconciliation, with Toby advising her to take a leap of faith when C.J. finds herself at a personal and professional crossroad. Despite strong mixed emotions, Bartlet's final official act as president is to pardon Toby and thus spare him from having to serve his prison sentence. In the episode "The Ticket", a flash forward reveals that, at the time of the dedication of Bartlet's presidential library three years later, Toby has been teaching at Columbia University. Toby has been invited to the dedication by Bartlet and it appears they have moved on from the shuttle leak incident with Toby quietly offering to help Bartlet write his speech for the dedication. Schiff had rationalised that the leak had in fact come from Toby's recently deceased astronaut brother, David, an idea hinted at in-show in a later scene between Toby and his ex-wife Andy; it is left hanging whether Bartlet and Ziegler's reconciliation in the 'flash forward' may have been enabled by his becoming aware of Toby having actually protected the reputation of his brother, or the passage of time since the incident simply allowed tempers to cool.