John Spencer was one of the nicest, most personable actors I've had the privilege of talking to in the nearly 17 years I've had this job.

So it was doubly shocking when the news of his sudden death broke last week.

Spencer is best known for two television roles — as Tommy Mullaney on "L.A. Law" and as Leo McGarry on "The West Wing." And he was nothing short of marvelous on both shows.

It was during his run on the former show that I first ran into Spencer at an NBC function during a Television Critics Association press tour. He seemed a lot like his character — sort of a blue-collar kind of guy (which was indeed his real background) who was somewhat amused by the whole Hollywood thing.

But unfailingly polite and enthusiastic, even when answering dumb (or at least repetitive) questions from a phalanx of TV critics. Which continued to be the case when, five years after exiting "L.A. Law," he returned to TV as White House chief of staff Leo McGarry, sort of a tough father-figure to the rest of the "The West Wing" staff.

Not that Leo was perfect by any means. He was a recovering alcoholic (something Spencer shared with the character) who didn't always agree with the man he was largely responsible for putting in office — President Josiah Bartlet (Martin Sheen). In fact, their differences led to Leo's being replaced as chief of staff early in the sixth season and — in the ultimate irony — suffering a severe heart attack.

As "The West Wing" transitioned into a show more about the race to succeed Bartlet than about the Bartlet presidency, Leo made a comeback of his own, helping organize the fractious Democratic convention and becoming the surprise running mate of eventual nominee Matthew Santos (Spencer's fellow "L.A. Law" alumnus Jimmy Smits).

Along the way, Spencer won a lot of fans who will miss seeing him on "The West Wing." Including me.

HOW WILL "THE WEST WING" deal with Spencer's death?

It's a very tough question for executive producer John Wells' team to tackle, both in terms of what's happening on camera and what happened off camera.

Not only are members of the cast, crew and production staff of the show dealing with the death of their colleague and friend, but the writers have to figure out what to do with the character of Leo McGarry.

As regular viewers of the show know, Leo is not only running for vice president, he's very much involved in running the Santos campaign. The next "West Wing" episode (scheduled to air Sunday, Jan. 8) is about the vice-presidential debate between Leo and GOP candidate Ray Sullivan (Brett Cullen).

The show is on a production hiatus for the holidays. Fourteen of the 22 episodes ordered for this season have already been filmed; nine have aired.