United States political commentator and Pulitzer Prize winner Charles Krauthammer died on Thursday at the age of 68. The columnist died of cancer of the small intestine, his son Daniel Krauthammer told The Washington Post.

Krauthammer’s column has been published in The Washington Post since 1984, and he regularly appeared as political analyst on Fox News. He had stayed away from work since a malignant abdominal tumour was removed in August last year. However, in an open letter on June 8, he said his doctors had told him that he had only few weeks to live as the cancer had returned.

“I had thought that silence would soon be coming to an end, but I’m afraid I must tell you now that fate has decided on a different course for me,” he wrote in the letter, according to CBS. “I leave this life with no regrets. It was a wonderful life – full and complete with the great loves and great endeavors that make it worth living. I am sad to leave, but I leave with the knowledge that I lived the life that I intended.”

He started his career in political commentary in 1978, when he became a speechwriter for former US President Jimmy Carter’s deputy, Walter Mondale. He then moved on to write opinion pieces for The New Republic and TIME Magazine. Later, Krauthammer joined The Washington Post and won the Pulitzer Prize in 1987 for “his witty and insightful” commentary.

Krauthammer is credited with coining the term “The Reagan Doctrine” in 1985, in reference to as former US President Ronald Reagan support for those fighting communism in foreign countries. The term, as Krauthammer said, proclaims overt and unashamed American support for anti-communist revolution.