Barack Obama led a memorial service Wednesday night for six people killed in the shooting of US congresswoman Gabrielle Giffords, calling for greater civility in public discourse to honour the victims of the attack, dpa reported.
"If this tragedy prompts reflections and debate, as it should, let's make sure it's worthy of those we have lost," Obama told a crowd of several thousand at the McKale Memorial Centre in Tucson, Arizona. "Let's make sure it's not on the usual plane of politics and pettiness that drifts away in the next news cycle."
In a speech that was met with repeated standing ovations, Obama frequently referred to Christina Taylor-Green, the 9-year-old girl who was trying to meet Giffords when she was killed in the attack.
"I want to live up to her expectations," Obama said. "I want our democracy to be as good as she imagined it. I want America to be as good as she imagined it."
Obama's comments came shortly after the US House of Representatives in Washington unanimously adopted a resolution condemning the attack "in the strongest possible terms."
Earlier, Republican conservative activist and former vice presidential candidate Sarah Palin had struck back at her critics with inflammatory remarks of her own. Palin accused the US media of perpetrating a "blood libel" for linking the assassination attempt on Democrat Gabrielle Giffords to the rhetoric by right-wing politicians and pundits.
In Congress, House Speaker John Boehner called on members to put partisanship aside in the wake of the attack.
"We know that we gather here without distinction of party," he said. "The needs of this institution have always risen above partisanship."
But in a statement and video posted on Facebook, Palin, a darling of the Tea Party and the radical right wing, maintained that the firearms-infused rhetoric she employed during the recent mid-term campaigns were taken out of context by critics, who said it incited violence against her political opponents.
"As I said while campaigning for others last March in Arizona during a very heated primary race, 'We know violence isn't the answer. When we take up our arms, we're talking about our vote," she commented.
Palin, who is considering a run for the White House in 2012, came in for criticism immediately after Saturday's shooting.
One of her campaign posters featured a map of the US, in which vulnerable Democratic districts, including Giffords', were represented with a rifle sight.
"We've diagnosed the problem," she urged supporters at the time. "Help us prescribe the solution."
In another exhortation, she advised followers to keep attacking Democrats: "Don't retreat. Reload."
Palin insisted Wednesday that such words had no effect on Jared Lee Loughner, the 22-year-old man accused of the shooting attack on Giffords. Six bystanders were killed and 14 wounded Saturday at the constituent meeting Giffords held on a car park outside a supermarket in Tucson.
Giffords remains in stable but critical condition in hospital after being shot in the head, with doctors increasingly optimistic about her chances for recovery.
Her medical team said Wednesday that she was showing more signs of recovery, making "spontaneous movements" such as feeling her wound with her hand. Five other victims from Saturday's rampage remain hospitalized at University Medical Centre, with two in serious condition and three in fair.
Calling Loughner a "deranged, apparently apolitical criminal," Palin said she was first "puzzled" by the finger-pointing at her own rhetoric, then concerned, and now sad over the "irresponsible statements from people attempting to apportion blame for this terrible event."
"Within hours of a tragedy unfolding, journalists and pundits should not manufacture a blood libel that serves only to incite the very hatred and violence they purport to condemn," she said. "That is reprehensible."
Palin's comments came just a day after Loughner made his first appearance in federal court charged with the murder of two federal officials - a judge and one of Giffords' staffers - and the attempted murder of three others. He will face additional charges in the Arizona state legal system for the other four deaths.
Media reports have portrayed Loughner as a misfit loner, who was unable to fit in at school, work or college, and who developed an obsession with grammar and language.
He apparently had been building a grudge against Giffords since 2007, when he felt she failed to adequately answer a question he posed at a political meeting in which he asked "What is government if words have no meaning?"
His reclusive parents issued a statement Tuesday.
"There are no words that can possibly express how we feel," said a statement issued through their son's defence lawyer. "We wish that there were, so we could make you feel better. We don't understand why this happened. It may not make any difference, but we wish that we could change the heinous events of Saturday."