Clinton draws rebuke over RFK remark

SIOUX FALLS, South Dakota (Reuters) - Hillary Clinton mentioned the June 1968 assassination of Robert Kennedy in explaining on Friday why she had resisted calls to end her White House bid, drawing a rebuke from Democratic front-runner Barack Obama's campaign.

Clinton, who later apologized, made the remark about Kennedy to the editorial board of the Sioux Falls Argus Leader newspaper when explaining that other races for the Democratic presidential nomination had lasted into June.

"My husband did not wrap up the nomination in 1992 until he won the California primary somewhere in the middle of June, right? We all remember Bobby Kennedy was assassinated in June in California," she said.

"I don't understand it," Clinton said, referring to calls for her to pull out of the Democratic nominating race, which ends on June 3 with primaries in South Dakota and Montana.

Kennedy, brother of slain U.S. President John F. Kennedy and Massachusetts Sen. Edward Kennedy, was assassinated during the 1968 race for the Democratic nomination.

Clinton's comments drew a sharp response from the Obama campaign.

"Senator Clinton's statement before the Argus Leader editorial board was unfortunate and has no place in this campaign," said Obama campaign spokesman Bill Burton.

Clinton told reporters later, "I regret if my referencing of that moment of trauma for our entire country and particularly the Kennedy family was in any way offensive. I had no intention of that whatsoever."

"I'm honored to hold Senator Kennedy's seat in the United States Senate from the state of New York and have the highest regard for the entire Kennedy family," Clinton added.

A spokesman said Clinton had simply been pointing out that Democratic campaigns in the past had continued into June and therefore people should not be pressuring her to withdraw.

"She was simply referencing her husband in 1992 and Robert Kennedy in 1968 as historical examples of the nominating process going well into the summer. Any other reading is inaccurate," Clinton spokesman Mo Elleithee said.

There have been concerns about the safety of Obama, an Illinois senator who would be the first black U.S. president. He began receiving Secret Service protection 18 months before the November election -- earlier than any other candidate has received increased security.

The protection came after congressional leaders raised the issue with Homeland Security and other groups and presented information that reportedly included threats on the Web and in letters.

Obama has an almost insurmountable lead over Clinton in the race for Democratic nomination. The former first lady has said she would continue until the last state has held its nominating contest.

(Editing by Peter Cooney)