And in a New York newspaper essay, she revisits her reference to the Robert F. Kennedy assassination.

From the Associated Press

HORMIGUEROS, PUERTO RICO — Campaigning in Puerto Rico, Hillary Rodham Clinton on Sunday offered a spiritual defense for continuing her presidential bid.

At Pabellon de la Victoria evangelical church, Clinton spoke to the crowd about faith in the face of adversity.

"There isn't anything we cannot do together if we seek God's blessing and if we stay committed and are not deterred by the setbacks that often fall in every life," she said.

Puerto Rico, which holds its primary Sunday, has 55 pledged delegates to the Democratic National Convention at stake. Clinton is expected to win handily, partly because New York, the state she represents as senator, has a large Puerto Rican community.

Clinton spoke of her determination to stay in the race despite trailing Illinois Sen. Barack Obama, who picked up three superdelegates in Hawaii on Sunday, for a total of 1,977 delegates, 49 short of the 2,026 needed to clinch the nomination. Clinton has 1,779.

Alluding to calls for her to drop out, she said: "If I had listened to those who had been talking over the last several months, we would not be having this campaign in Puerto Rico today."

In an essay called "Why I continue to run," in Sunday's New York Daily News, Clinton addresses her reference Friday to the assassination of Robert F. Kennedy. (A South Dakota newspaper editorial board had asked her whether she was going to stay in the race. She responded by citing Kennedy's 1968 campaign -- which continued until June, when he was slain -- as well as her husband's 1992 campaign.)

"I was making the simple point that given our history, the length of this year's primary contest is nothing unusual," Clinton says in the essay.

She was "deeply dismayed and disturbed" that her comment was misconstrued, she says.