As a triple amputee Vietnam War veteran, Democratic Georgia Sen. Max Cleland might seem immune to political attacks on national security and fighting terrorism.

But his Republican rival, Rep. Saxby Chambliss, is challenging conventional wisdom with a new television ad that features cameo appearances by Usama bin Laden, the fugitive terrorist leader, and Iraqi President Saddam Hussein.

Cleland "says he supports President Bush at every opportunity,'' says the ad, which began running Friday on stations across Georgia. "But that's not the truth. Since July, Max Cleland has voted against the president's vital Homeland Security efforts 11 times.''

Cleland issued an angry statement of denial. "Accusing me of being soft on homeland defense and Usama bin Laden is the most vicious exploitation of a national tragedy and attempt at character assassination I have ever witnessed,'' he said.

"Protecting Americans is not political, and using Usama bin Laden in pursuit of a short-term political goal is an insult to every man and woman from every Georgia military installation now risking his or her life searching for bin Laden and his terrorist cadre.''

Georgia's other Democratic senator, Zell Miller, said he was offended by the ad.

"Max Cleland is a courageous man who has given his own blood and so much more fighting for the right of all of us to live in freedom,'' Miller said in a statement issued Sunday night. "My friend Max deserves better than to be slandered like this.''

Cleland backed creation of a Department of Homeland Security before the president did and voted for Democratic-drafted legislation to establish the new agency when it cleared committee this year.

He was on the opposite side from the administration on several amendment votes in committee as well as on the Senate floor, where the legislation is stalled. Most of the amendments related to civil service rules and labor protections for employees of the new department, the disagreement that has blocked passage of the measure thus far.

The issue pits the administration and its allies in Congress against labor unions, which generally are strong supporters of Cleland and other members of the Senate's Democratic majority.

Cleland has led consistently in the polls, but Republicans say Chambliss has recently narrowed the gap.