* Jurist, 79, has survived two bouts with cancer
* Voices optimism for liberal wing in new court term
By Joan Biskupic
WASHINGTON, Aug 8 (Reuters) - U.S. Supreme Court Justice Ruth Bader Ginsburg, 79, the eldest member of the bench and leader of its liberal wing, said she cracked two ribs in June but met all her work obligations and remains committed to staying on the court at least three more years.
Interviewed by Reuters in her chambers on Tuesday, Justice Ginsburg said she felt fine and showed no sign of the injury, which has not been previously reported.
"At first I thought it was nothing," said Ginsburg, who fell at home. She added, however, that the injury occurred at the start of the Supreme Court's difficult final month, "so it was the worst possible time."
Ginsburg, who has survived two serious bouts with cancer, undergoes regular check-ups and said Tuesday her health on that front was "great." She continues to use a personal trainer.
She fell on June 4. She went to work the next day but continued to be in pain. She turned to the Office of the Attending Physician, which provides medical care to members of Congress and the justices, said court Public Information Officer Kathy Arberg.
Ginsburg discovered she had fractured two ribs, which would only heal with time. Ginsburg "followed her schedule as usual," Arberg said on Wednesday. "She indeed did not skip a beat and did not feel it rose to a serious health concern."
As the eldest justice, Ginsburg is the most closely watched for any signs of possible retirement, especially in a politically charged election year when the two candidates differ significantly in their visions for the court.
The court begins its new term on Oct. 1, five weeks before the Nov. 6 presidential election.
Appointed for life in 1993 by President Bill Clinton, Ginsburg spoke at a legal conference in New York on June 8, then at a conference in Washington, D.C., on June 15 and continued with scheduled travels to Europe in July.
Shed of her black robe and wearing a silver and black patterned dress, Ginsburg was relaxed during the wide-ranging interview. She spoke enthusiastically about her travels to Venice and Vienna, where she taught classes, and of upcoming vacations to listen to opera, her passion.
She was optimistic both about how the liberal side would fare in the court's upcoming term and the collegiality of the justices who were bitterly divided at the end of June over President Barack Obama's healthcare plan.
Justices rarely speak publicly about cases beyond their opinions, and she deflected questions about negotiations that led to the court's stunning 5-4 decision on June 28 upholding the healthcare law.
The court's conservative wing, led by Chief Justice John Roberts, outnumbers the liberals and conventional wisdom had it that it would overturn the Democratic president's healthcare plan.
"Don't ask me if the chief switched sides," said Ginsburg before she could be asked about a CBS News report after the healthcare decision that Roberts had been ready to strike down the law but changed his vote.
Roberts cast the decisive fifth vote with the liberal bloc based on Congress' power to levy taxes.
Without addressing the specific situation, Ginsburg acknowledged that justices often shift positions as they work on cases and send draft opinions to colleagues for responses.
"It ain't over 'til it's over," she said.
"People change their minds about what they thought. So it isn't at all something extraordinary, and that's how it should work. We're in the process of trying to persuade each other and then the public."
Roberts declined a request for an interview.
BRANDEIS A MODEL
As the positions in the healthcare case unfolded among the nine justices, Ginsburg said, the process was fluid. But she suggested it was obvious from the earliest discussions after the late-March oral arguments that Roberts and the other conservatives were poised to limit Congress' commerce power.
The Obama administration's main argument for upholding the law, which requires most Americans to buy health insurance by 2014, rested on Congress' robust authority to regulate commerce and the national economy.
Ginsburg quickly began drafting the dissenting statement on that issue, portions of which she read from the bench on the day the ruling was announced.
"I had a draft of the dissent before the chief circulated his opinion because I knew it would be impossible to do" as the term went into the final month of June and several cases culminated.
Despite the outcome upholding the law, based on congressional authority to levy taxes, Ginsburg said it was important to liberals to highlight their stance that the conservatives' reasoning on the Commerce Clause could return the justices to an era nearly 75 years ago when the court routinely rejected congressional efforts to regulate the economy.
Ginsburg said it was too soon to know how that part of the healthcare decision might affect other regulatory efforts by Congress. "It may turn out that it could be just the exception that proves the rule" of broad federal authority, she said.
She repeated her vow to remain on the bench at least three more years to match the tenure of Justice Louis Brandeis, who retired at age 82 in 1939, after nearly 23 years on the bench.
She added that she might end up serving longer than Brandeis and deeper into her 80s. "Brandeis had a problem that I didn't," she said. "He was losing his eyesight." (Editing by Amy Stevens, Howard Goller and Todd Eastham)
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