Danny Concannon worked as the senior White House Correspondent. As of May 2000, Concannon had been covering the White House for 8 years for The Washington Post, TIME Magazine, New York Times and the Dallas Morning News.
He is a Pulitzer Prize-winning journalist who has worked as a White House Correspondent throughout three administrations and is acknowledged by the White House Press Corps as the Bartlet administration's favorite reporter, and the correspondent most likely to be given an exclusive with the Press Secretary, the President, or one of the Senior Staff.
Concannon is the correspondent who was the most steadfastly supportive of the Bartlet administration, and he appeared to have a good friendship with President Josiah Bartlet, Leo McGarry, Charlie Young and Josh Lyman as well. Most of these friendships are implied to have begun while he was a reporter following the Bartlet Campaign prior to President Bartlet's first term in office.
He was used by C.J. as an example of an ideal reporter even when he was no longer in the Briefing Room.
Danny returned to the Briefing Room after a lengthy absence during the first Christmas Season of President Bartlet's second term as President in 2002. While C.J. is happy to see him, their reunion is complicated due to Danny's reveal: he's investigating and writing a story on the Administration's possible order to assassinate Qumari Defense minister Abdul ibn Shareef, in violation of the United States and international law. He finds links connecting the Administration to Sharif's death but agrees to delay posting due to threats to the administration. During Zoey Bartlet's kidnapping, C.J. tells Danny to publish his story ahead of the planned release by then-Acting President Glen Allen Walken, showing her dedication to him despite the risk it posed for her own career.
As President Bartlet prepared to leave the White House, Danny reappeared once again and asked C.J. on a date, where he reveals his plans to quit reporting, citing recent disillusion with where the profession is going. He and C.J. rekindled their romance after Leo's death and continued to see each other leading although C.J. was hesitant to let things get serious before Inauguration.
Her hesitancy led Danny to question her commitment to him &their relationship, despite his understanding of the demands of her job. It all came to a head when C.J. was ready to take a job with the Santos Administration out of duty and without consulting him first — especially when she'd had more exciting and attractive offers. After a heart-to-heart with Toby, C.J. arrived at Danny's apartment and they talked things through. C.J admitted that she feared she'd missed the window to learn how to be in a successful relationship. Danny assured her they would learn together (and joked that he would train her). C.J. then admitted she didn't want to work in the White House anymore: she'd rather take Hollis' offer and start anew with Danny elsewhere.
The most defining trait of his character was his long-standing on-again/off-again romance with White House Press Secretary turned White House Chief of Staff, C.J. Cregg. The most famous moment of their relationship is the fact that he purchased the goldfish Gail for CJ during season one, having misunderstood Josh Lyman's statement about CJ liking Goldfish. Gail is seen on her desk for the rest of the series, usually with a new, thematically-relevant decoration in the bowl every week.
After the Bartlet administration came to an end, Danny moved to Santa Monica, California, alongside C.J. By the time of the Bartlet Presidential Library dedication, taking place three years in the future (circa 2009-2010), Danny and C.J. are living together in Santa Monica and have a baby together.
Danny has a decent working relationship with the President, having covered the 1998 campaign and spent many late nights talking with the then-Presidential Candidate. The President is so comfortable with and trusting of Danny that he attempts to get Danny's help in avoiding a fight with his wife, which President Bartlet seems to take no issue with Danny knowing.