Best-known to television audiences as quirky and charismatic New York attorney Tommy Mullaney on “L.A. Law,” John Spencer returned to series television, moving from the courthouse to the White House on the NBC, award-winning one-hour drama “The West Wing” (Weds., 9 p.m.). The Aaron Sorkin-created series stars Martin Sheen as a popular Democratic president, with Spencer as his chief of staff Leo McGarry, a complex workaholic whose passion for crossword puzzles is equaled only by his Casey Stengel approach to running the president’s “team.” With two Emmy nominations under his belt for his role as Leo, John pulled double duty by shooting “The West Wing” during the day and performing at night in the play Glimmer, Glimmer and Shine written by Warren Leight. The play ran from January 25th-March 4th at the Mark Taper Forum in Los Angeles and from May 22nd-July 8th at the Manhattan Theatre Club in New York City.

In his mind, it is his good fortune of working with the world’s finest writers that has led to his success. From David E. Kelley to Warren Leight to his recent collaboration with Aaron Sorkin, he credits the words on the page for allowing him to stretch as an actor. "It’s a chance to look behind closed doors and see people at work in this rarified environment, to see them not just as political figures but as human beings,” explains Spencer, who lauds “The West Wing’s” writing as some of the best he’s ever seen on television. “As former college friends, my character and Sheen’s president share a personal history that leads to some very frank discussions.”

The actor, an Obie winner for his theater work whose feature film oeuvre includes memorable roles in Presumed Innocent, Forget Paris and The Rock, is himself known for his honesty, a trait instilled as a boy raised in the suburbs of Paterson, New Jersey. The only child of blue-collar Roman Catholic parents, Spencer was “weaned on TV” but fell in love with the live stage as a boy. His career path was clear by grade school when he directed a version of “My Fair Lady” and took the role of Henry Higgins. Emboldened by acting classes in New York, Spencer faced the familial trauma of leaving home at sixteen to pursue his passion. While attending Professional Children’s School in the city he earned catalog modeling jobs, leading to his first television role as Henry Anderson, the boyfriend of the English twin on “The Patty Duke Show.” To appease his parents, Spencer enrolled at Fairleigh Dickenson University, running through four different majors in four years, yet earning a consistent spot on the Dean’s List.

He returned to New York to understudy the lead in Butterflies Are Free, a role he subsequently played on tour. Regional theatre opened up for Spencer, leading him to seek out new plays by new playwrights and providing him entry into the New York theatre scene. From 1974-81 he performed in such stage works as David Mamet’s Lakeboat, Michael Weller’s Fishing and Loose Ends, John Hopkins’ This Story of Yours, the gentleman caller in Tennessee Williams’ The Glass Menagerie and Emily Mann's Still Life. The latter production, about a Vietnam vet, went on to earn Spencer and the play Obie Awards during its off-Broadway run in 1981. A Drama Desk nomination later came for his performance in The Day Room. He also portrayed Dan White in the critically acclaimed production of another Emily Mann play, Execution of Justice.

When Still Life came to the Los Angeles stage, Spencer opened a new door with his first feature film role -- a bit part as a military grunt who won’t push “the button” during the opening scene of War Games. His natural charisma and strength led to authority roles: Al Pacino’s boss in Sea of Love and Michael Douglas’ in Black Rain, Harrison Ford’s detective sidekick in Presumed Innocent (“a watershed role,” says Spencer), Billy Crystal’s basketball referee friend in Forget Paris, Harvey Keitel’s partner in Copland. More recently Spencer has moved between studio and independent projects, taking dark roles in Café Society, Albino Alligator, Lesser Prophets and Ravenous while coming down -- usually -- on the side of the law in The Rock, Twilight and The Negotiator.

After seeing his work in Presumed Innocent, producer David E. Kelley invited Spencer to join the cast of “L.A. Law” for the final four of its eight-year run. From 1990-94 he mesmerized audiences with his tough, funny portrayal of Tommy Mullaney, reinvigorating the series and solidifying his reputation as a preeminent character actor. Spencer appeared in one of NBC’s most highly rated telefilms, “The Tangled Web,” starred in Joseph Wambaugh’s “A Jury of One” and guest starred on such episodic series as “Miami Vice,” “Spenser for Hire,” “Law & Order,” “Touched By An Angel,” “The Outer Limits,” “FX,” “Early Edition,” “Lois & Clark” and “Tracey Takes On...” Recently he portrayed Simon McCallister on the NBC drama “Trinity.”

Two years ago he created the role of ex-jazz musician, ex-junkie Martin Glimmer in the world premiere of Warren Leight’s The Glimmer Brothers at the Williamstown Theater Festival. Spencer recently played the part of Martin Glimmer in Glimmer, Glimmer and Shine (same play, new title) in Los Angeles at the Mark Taper Forum. The play tells the poignant story of Martin and Danny Glimmer, twin brothers who joined Eddie Shine for a brief but intense period of time forming an all-electric trumpet section in the big band jazz days of the 1950s. Eventually torn apart by the very music and hard-living lifestyles that once united them they became estranged for 40 years. The brothers’ journey toward reconciliation is beautifully chronicled in a succession of playful, intermingling, funny, touching riffs--scenes that seem to have much in common with the alternately exhilarating and heartbreaking improvisations found in jazz and life.

When he is not spinning crises or holding it together for the next television president as “The West Wing’s” Leo McGarry, Spencer enjoys reading, listening to music and spending time with friends -- even those from his high school days.