I am suddenly and exceedingly sad. John Spencer, who played chief of staff (and current Democratic vice presidential candidate) Leo McGarry has died at the age of 58. Just like Leo, John had a heart attack. Unlike Leo, he did not recover.

The McGarry character earned Spencer an Emmy, American television's highest honor, for best supporting actor in a drama in 2002. The show also earned Emmys for best TV drama and Screen Actors Guild awards for ensemble acting.

[...] Spencer also starred in popular 1990s television drama "L.A. Law" as tough-minded but funny attorney Tommy Mullaney.

Ron Hofmann, a spokesman for Spencer, said he had no knowledge of whether the actor suffered from a heart condition or other ailment that would have caused a heart attack. Like his character on "West Wing," Spencer was an acknowledged alcoholic, but quit drinking long ago.

Spencer was the only child of Mildred and John Speshock. He left his home in Paterson, New Jersey, at age 16 to attend Professional Children's School in New York City, and changed his name to Spencer.

His first big break came in 1963 playing Henry Anderson, the boyfriend of an English twin on "The Patty Duke Show." For a time, he attended Fairleigh Dickenson University, but returned to New York to pursue a career in theater.

Throughout the 1970s, he performed in plays ranging from David Mamet's "Lakeboat" to "Still Life," for which he earned an OBIE award.

A road production of "Still Life," about a Vietnam veteran, brought Spencer to Los Angeles, and it was there that he earned his first role in a major feature film, "War Games." Other film roles came in "Sea of Love" and "Presumed Innocent."

But it was on TV where Spencer made his mark. As Mullaney on "L.A. Law," from 1990 to 1994 he helped breathe new life into the show's final years.

Spencer is not married and has no kids. He is survived by cousins, aunts, uncles and friends, his family members said in a statement.

Tuesday would have been John Spencer's 59th birthday.

Later news: The writers and producers of The West Wing don't know how they'll handle John Spencer's death, but entertainment watchers think it makes the show (now ranked 50th in prime time since it was shuffled off to Sunday night opposite Extreme Makeover: Home Edition, Cold Case, and The Simpsons) even less likely to be renewed for an eighth season (despite what the article says, this is season 7 of The West Wing).