On one side of the TV screen, Tim Michels (search) tells voters Wisconsin needs a senator ready to back up President Bush in the war on terror.

On the other, black smoke billows from the World Trade Center (search).

Michels has not hesitated to use images from the Sept. 11, 2001, terrorist attacks in his campaign ads as he seeks the Republican nomination to take on Sen. Russ Feingold (search), D-Wis. He is not alone in running such ads.

The University of Wisconsin-Madison's Wisconsin Advertising Project, which tracks political ads across the country, said it is seeing more campaign commercials with images from the attacks this year than it did two years ago.

While some families and victims of Sept. 11 have complained the commercials are trying to capitalize on their personal tragedy, Michels said the images are central to the biggest issue of this election — the War on Terror (search).

"I think there's probably no greater symbol of what kind of damage terrorists can do to our country than the Twin Towers burning," said Michels, one of four Republicans running in Tuesday's primary to take on Feingold.

Joel Rivlin of the Wisconsin Advertising Project said less than a half dozen of the more than 2,500 ads the group studied from the 2002 campaign featured images from the attacks. He said those images have appeared in commercials more frequently this year, though the group has yet to release data on just how many.

Examples include a Bush ad that ran in March and showed the twisted rubble of the towers and firefighters carrying a flag-draped stretcher. The ads drew criticism from some families, while others defended them as an appropriate reminder of how the president responded to the attacks.

In Indiana, a Republican candidate challenging GOP Rep. Steve Buyer ran an ad that showed smoke coming out of the New York skyline and a plane about to hit one of the towers.

In North Carolina, a Republican gubernatorial candidate ran an ad showing the hijacked airplanes slamming into the World Trade Center and featured a voiceover by a victim's father. The spot tried to tie Democratic Gov. Mike Easley to the attacks by claiming legislation he signed made it easier for terrorists to get driver's licenses.

Andrew Rice, whose brother was killed in the World Trade Center, said the ads are offensive because candidates are trying to use the tragedy for political gain.

"It's one step short of actually going to ground zero of the Pentagon or Shanksville, Pa., and actually doing a campaign event," said Rice, a board member for a group that opposes any use of the images in campaign commercials.

William Elliott, dean of Marquette University's communication college, said such ads are much more likely to offend viewers in New York or Washington because of their personal connections to the attacks. Candidates elsewhere face a much lower risk of alienating voters by using the images.

"For us, it was a major news event. But it was just a major news event," Elliott said. "For people in New York, they knew people or even witnessed some of it. They certainly had to deal with it on a very personal level."

Michels, a former Army Ranger and millionaire businessman, has made the War on Terror a central theme in his Senate campaign. He often has criticized Feingold for casting the lone vote against the Patriot Act (search).

Feingold spokesman John Kraus accused Michels of using the ads as "part of a pattern of using fear mongering, scare tactics and human tragedy to try to draw attention to his campaign instead of talking about the goal we all share of fighting terrorism while protecting our freedoms."