First lady Laura Bush (search) stumped on behalf of her husband President Bush on Tuesday, addressing sensitive issues cited for a recent drop-off in his job approval ratings: prisoner abuse and the war in Iraq.

President Bush is seeking a much-needed boost in his quest for re-election. His approval ratings have sagged recently amid outrage over photos of U.S. military soldiers abusing imprisoned Iraqis and criticism for how he has handled the war in Iraq.

"We must be vigilant in protecting the rights of all Iraqis," she said in a speech at the University of Nevada, Las Vegas. "The pictures we saw recently from the Abu Ghraib prison (search) do not reflect the character of our troops. The vast majority of our military has conducted themselves with honor and compassion."

She told the ticketed crowd of 1,000 that because of her husband's efforts, 50 million more men, women and children live in freedom in Afghanistan and Iraq.

A Newsweek poll released over the weekend put the president's overall job approval at 42 percent, the lowest yet in that poll.