Los Angeles ? John Spencer, who played a tough and dedicated politico on “The West Wing” who survived a serious illness to run for vice president, died of a heart attack Friday. He was 58.

Spencer died at a Los Angeles hospital, said his publicist, Ron Hofmann. He would have been 59 next week.

“John was a consummate professional actor and everyone adored him,” said actress Allison Janney, C.J. Cregg on the NBC series. “We will miss him deeply.”

Spencer played Leo McGarry, the savvy and powerful chief of staff to President Josiah “Jed” Bartlet (Martin Sheen). In a sad parallel to life, Spencer’s character suffered a heart attack that forced him to give up his White House job.

The character recovered and was picked as a running mate for Democratic presidential contender Matt Santos, played by Jimmy Smits; the campaign against Republican Arnold Vinick (Alan Alda) has been a central theme for the drama this season.

NBC and producer Warner Bros. Television issued a statement calling Spencer a “remarkable man with enormous talent.” They did not address how his death would affect the Emmy Award-winning series, in production on its seventh season.

Spencer, who also starred on “L.A. Law” as attorney Tommy Mullaney, received an Emmy Award for his performance on “The West Wing” in 2002 and was nominated four other times for the series.

Spencer grew up in Paterson, N.J., the son of blue-collar parents. With his enrollment at the Professional Children’s School in Manhattan at age 16, he was sharing classes with the likes of Liza Minnelli and budding violinist Pinchas Zukerman.