Democratic presidential candidate Hillary Clinton tried to raise doubts about rival Barack Obama yesterday.
In a debate in Austin, Texas, Mrs Clinton, who is seeking big victories in Texas and Ohio on March 4th, questioned Mr Obama's readiness to become president, said he has a weak resume and criticised him for borrowing rhetoric for his uplifting campaign speeches.
Senator Hillary Clinton during a debate with rival Senator Barack Obama
But in a passionate concluding statement in a debate, she made reference to her past political battles from her husband's time in the White House, without detailing them.
Mrs Clinton, a New York senator, said at the debate in Austin, Texas that she had "lived through some crises and some challenging" moments in her life but that they had been "nothing compared to what goes on every single day in the lives of people across our country".
"Whatever happens, we're going to be fine," she said, looking at Mr Obama seated beside her.
"We have strong support from our families and our friends. I just hope that we'll be able to say the same thing about the American people and that's what this election should be about."
Mr Obama appeared touched by her words and the two shook hands warmly in the middle of her statement.
In her toughest line of the night, she drew scattered boos from some in the audience for ridiculing Mr Obama for using rhetoric in his speeches that had already been used by a supporter, Massachusetts Gov Deval Patrick.
"If your candidacy is going to be about words, then they should be your own words," she said. "And you know, lifting whole passages from someone else's speeches is not change you can believe in, it's change you can Xerox."
Mr Obama said the fuss over the lines he used from Patrick was "silly season" politics. Scolding Mrs Clinton, he said Democrats should not be "tearing each other down" but rather "lifting the country up."
Illinois senator Mr Obama has secured 10 straight wins in the state-by-state nomination process.
New Washington Post-ABC News opinion polls Mrs Clinton at 48 per cent and Mr Obama at 47 per cent, but Mrs Clinton leading Mr Obama in Ohio by 50 per cent to 43 per cent. Mr Obama has a growing lead in pledged delegates who will choose the Democratic candidate at the party's convention in August.