In 1981, Morris became the authorized biographer of
Clare Boothe Luce (1903–1987), the playwright, congresswoman and diplomat. In 1997 she published the first volume of Luce's biography,
Rage for Fame: The Ascent of Clare Boothe Luce.
Gore Vidal described it in
The New Yorker as "a model biography . . . of the sort that only real writers can write." Karen Heller commented in
The Philadelphia Inquirer, "In this marvelous volume, Sylvia Jukes Morris has not just amassed information, but distilled it. The result is a portrait that is powerful and resonant."
Judith Martin disagreed in
The New York Times Book Review, criticizing the book's "barrage of anecdotes" and writing, "[T]he stories keep pouring forth without relief." Martin wrote that Morris's approach was "like being on confidential terms with someone who hates her boss." The
Times named
Rage for Fame a "Notable Book" for 1997. Seventeen years after the publication of
Rage for Fame, Morris published the second volume of the biography,
Price of Fame: The Honorable Clare Boothe Luce, in 2014. Reviews were mixed. In
The Wall Street Journal,
Edward Kosner called Morris's effort "stellar";
Kirkus Reviews characterized it as an "evenhanded and intimate portrait." However, in
National Review Florence King called the 752-page volume "an exhausting door-stopper." Noting that Luce had left all of her papers—totaling 460,000 items—to the
Library of Congress, King wrote, "I get the distinct feeling that Clare terrorized Morris into using every single thing in the archive." King found Morris's approach "maniacally exacting" and, after enumerating examples that the author had afforded of Luce's clothing, jewelry, perfume, and party guests, wrote, "This is where your reviewer yelled
SO WHAT!" "Morris is not great at stepping back and analyzing," wrote
Maureen Dowd in
The New York Times Book Review. "She just methodically piles up the facts." ==Other work==