The calls came from some victims' families and a union supporting John Kerry. But some who lost relatives backed the ads.
One of the ads shows the charred wreckage of the twin towers with a flag flying amid the debris. Another ad — and a Spanish-language version of it — use that image as well alongside firefighters carrying a flag-draped stretcher through the rubble as sirens are heard. Firefighters are shown in all the ads.
"The last few years have tested America in many ways," reads the script for one of the two ads that feature Sept. 11 footage.
"Some challenges we've seen before. And some were like no others," the ad continues, showing a flag in front of the ruins of the World Trade Center. "But America rose to the challenge. What sees us through tough times? Freedom, faith, families, and sacrifice."
CBS News Correspondent Joie Chen reports the images in question — in ads set to run in 18 key states — are brief and fleeting, but to families of some victims, enough to bring back haunting memories.
"I wouldn't have a problem with the president using 9/11 if I thought that he had done everything in his power, first off, to thwart the attack and then, on the morning of 9/11 itself, had a full sense of plan once the attacks were under way," Patty Casazza, who lost her husband John at the World Trade Center, told the CBS News Early Show. "Additionally, after 9/11, the president has done everything in his power to thwart investigation into the death of 3,000 people."
The president's aides and allies defended the commercials, which were intended not to stir controversy, but to mark the opening of the president's campaign after months of Democratic attacks.
"This image is a very, very tasteful image," said Bush adviser Karen Hughes on Thursday's Early Show. "Sept. 11th was not just a distant tragedy, it's a defining event for the future of our country."
Former New York Mayor Rudy Giuliani said Mr. Bush's "leadership on that day is central to his record, and his continued leadership is critical to our ultimate success against world terrorism."
Mr. Bush shows no signs of shying away from mentioning the attacks on the stump. At a campaign stop Thursday, Mr. Bush himself reminded voters how his presidency was shaped by the events of Sept. 11.
"I stood in the ruins of the twin towers. I'll never forget that day. I remember the workers in the hard hats who were shouting, 'Whatever it takes,'" the president said. "As we all did that day, these men and women searching through the rubble took it personally. I took it personally."
Republicans hold their nominating convention in New York City this summer at an unusually late date that brings it close to the third anniversary of the attacks.
In Bal Harbour, Fla., the International Association of Fire Fighters Union approved a resolution asking the Bush campaign to pull the ads, spokesman Jeff Zack said. The resolution also urges Mr. Bush to apologize to the families of firefighters killed in the attacks. The union gave Kerry an early endorsement in the presidential race.
Harold Schaitberger, president of the International Association of Fire Fighters Union, called the ads disgraceful and said they should be pulled.
"I recall the president early on saying that he would never utilize the terrible tragedy of 9/11 for political purposes," he said.
Barbara Minervino, a Republican from Middletown, N.J., who lost her husband, Louis, in the attacks, questioned whether Mr. Bush was "capitalizing on the event."
David Potorti, an independent from Cary, N.C., whose brother Jim died in the north tower, called the campaign's use of the images audacious.
"It's an insult to use the place where my brother died in an ad," Potorti said. "I would be just as outraged if any politician did this."
But Deena Burnett, whose husband Thomas died on United Flight 93, backed the ads.
"I'm glad he's using the 9/11 images," Burnett told the Early Show. "I think they're respectful and remindful of the events of Sept. 11th and the lives lost. These are images we have seen before thousands of times over in newspapers, in magazines, on television."
"This is a defining moment of his presidency. This is part of his presidency," Burnett said. "Most of the decisions that have been made have been derived from Sept. 11th. He has every right to show where we were on Sept. 11th, where we are today, and the fact that his leadership brought us this way. I think it's important for him to state his record and Sept. 11th is part of his record."
Patricia Riley of Staten Island, N.Y., who lost her sister in the attack, said: "The president has every right to point to his leadership during that time."
Opinion among victims' kin may be divided over how well they think the president has performed after Sept. 11.
Casazza, who dislikes the ads, feels the president's resistance to the panel probing the attacks undermines his claims of leadership.
"I don't understand why he wouldn't want an investigation into the death of 3,000 people that occurred on his watch," she said, noting that Mr. Bush for months resisted calls for an independent investigation. "The president is only willing himself to be heard by two members the commission, not under oath, and for one hour. That equates to 1.3 seconds per victim who died on 9/11. "
But Burnett, who is not offended by the ads, counters that, "the 9/11 commission exists only because of the president's willingness to find out what happened on 9/11."