By Tim Starks, CQ Staff

If Rudy Giuliani delivers his keynote speech to the Republican National Convention as scheduled this week, it will afford him an opportunity to start turning around a political career that has gone from boom to bust in the past year.

Giuliani was given the slot as much for his symbolic impact — after Sept. 11, he became the embodiment of the sort of national resolve and determination that John McCain seeks to underscore in his own campaign — as for his dogged promotion of his former rival for the Republican nomination for president.

Soon after Giuliani gambled his entire campaign on Florida’s January primary and lost, finishing a distant third, he threw himself behind McCain and headed out to campaign across the country as an aggressive attack dog. It’s not certain whether he would reprise that approach if he takes the podium in St. Paul, especially now that convention planners are working to tamp down partisanship in deference to Hurricane Gustav.

And while giving the keynote address rarely translates into national political currency — Barack Obama ’s speech to the Democrats four years ago being the main exception — the speech should help keep Giuliani in the public eye back home in New York, where he has not ruled out a run for governor or the Senate.

“Mayor Giuliani’s a real leader in the Republican Party, and he’s going to be a major player in the Republican Party for years to come,” said Michael Goldfarb, the deputy director of communications for the McCain campaign.

But others question whether the former mayor of New York City retains the same cachet he had among Republicans before the 2008 presidential nominating contest, at the start of which he was the front-runner in the polls.

“It’s a strange choice” for the keynote speech, said Cal Jillson, a professor of political science Southern Methodist University. “You just wonder if Rudy Giuliani is half the man he was 10 years ago, even a couple years ago. I think this campaign really took some of the luster off Giuliani.”

The Republican National Committee and the McCain campaign jointly made the decision to pick Giuliani. Joanna Burgos, a spokeswoman for the convention, said the party reasoned that his record of tackling the mafia as the top federal prosecutor in New York, and of cracking down on crime and moving people off welfare rolls and into jobs as mayor, fit in with a central tenet of the McCain campaign.

“I think one of the major things we want to focus on is that Washington is broken and there is a need for reform,” Burgos said. “Sen. McCain is the guy that can bring about that real form of change. We looked at the former mayor’s background, his public service, and that’s why we chose him to be the speaker.”

Although controversial as a mayor before Sept. 11 for his aggressive style and for some of his policies, the terrorist attack on the World Trade Center propelled Giuliani to national prominence and revived his reputation in New York, although some victims’ families blamed him for poor emergency communication after the attacks.

At the 2004 GOP convention in New York City, he gave a well-received speech that warmly praised President Bush for his leadership after the attacks and bitingly criticized that year’s Democratic nominee, Sen. John Kerry , as a flip-flopper.

“He’s not afraid to be critical of the Democratic platform,” said Cristyne Nicholas, a former Giuliani media aide who now works as a GOP-focused media consultant at New York City-based Nicholas & Lence Communications. “I think Rudy Giuliani speaks his mind.”

While Democrats have emphasized optimistic new voices in the party when they have selected recent keynote speakers — Obama in 2004 and Mark Warner this year — Republicans have tended to pick speakers known for their sharp tongues. Zell Miller, the Democratic former governor and senator from Georgia, was the GOP choice for years ago, for example. The attitude on the GOP side of late, said Jillson, is for the keynote speaker to “fillet the opposition.”