Remember Rudy Giuliani, the guy who was mayor of New York City when terrorists attacked the World Trade Center? The last time we saw him, he was trekking around the country trying to help elect Republican candidates in 2002. [IMGCAP(1)]

Well, some Empire State political wags are already abuzz with scenarios for the former mayor returning to the campaign trail, all of them based on a single assumption: Giuliani, who turned 59 earlier this year, wants to be president of the United States.

How might the former mayor maximize his chances of becoming the GOP nominee in 2008?

The safest bet for Giuliani probably is to run for the White House from the private sector. Or, he could run for New York governor in 2006, assuming that incumbent Republican George Pataki doesn’t seek a fourth consecutive term.

But if the former mayor wants to improve his chances for ’08, he ought to consider challenging New York Sen. Hillary Rodham Clinton (D) when she comes up for re-election in 2006. This, of course, would be a risky option, but it would also offer Giuliani the greatest possible payoff. Indeed, it’s probably the only way that he can get to the White House without an invitation from President Bush.

The terrorist attacks transformed Giuliani from a controversial mayor who cleaned up New York City but went through a very public, very messy divorce into a national hero. That’s not a bad place to begin a campaign for national office.

Giuliani certainly could run for the Republican presidential nomination without holding office, and he wouldn’t have a problem with name recognition. He also could campaign full time in 2006 and 2007, unencumbered by the need to balance a state budget or be on hand for an endless stream of Senate votes.

But a year or two from now, other Republicans will be in the spotlight and have the chance to grab the attention of grassroots Republicans across the country. Does Giuliani really want to bank on the public seeing him in 2007 as they did after the Sept. 11, 2001, tragedy?

The governorship of New York would be a natural next step for the former mayor of New York City, and he would start out the race as a clear favorite. A big electoral victory in 2006 would put him back on the national stage and demonstrate his electoral appeal.

And from the point of view of presidential politics, being a governor is an asset. Governors tend to win presidential nominations, in part because they aren’t viewed as Washington, D.C., insiders, and they don’t have to take positions on highly charged, ideological issues.

But some Empire State political insiders believe that a race against Clinton would bring with it unique advantages for the former mayor, and they are right.

They note that Giuliani’s first problem in any effort to get to the White House would be winning the GOP nomination.

While he received high marks following the terrorist attacks and for cleaning up the city, the former mayor remains far more liberal on moral issues than the rest of his party. His well-known support for abortion rights would make it difficult for him to win crucial caucuses and primaries.

For all his assets and accomplishments, Giuliani is still a moderate-to-liberal Republican in a party dominated by conservatives. And he’s still a New Yorker in a party anchored in the South and Midwest. He can’t win the GOP presidential nomination.

But running against and defeating Clinton would make Giuliani a superstar of unmatched magnitude to Republicans and conservatives. It’s a credential he could use to great effect in Iowa and New Hampshire.

Clinton remains the personification of everything Republicans detest, and by defeating her, Giuliani would become such a hero in GOP circles that even mainstream conservatives might find it impossible to oppose him.

Movement conservative groups, of course, would still be put off by his ideology and fight him. But a presidential hopeful who received high grades after Sept. 11, 2001, and who also ended the political career — and presidential ambitions of another Clinton — would have an amazingly appealing résumé to general election voters and GOP primary voters.

Could the former mayor beat Clinton? A May 12 Marist College Institute of Public Opinion survey of 512 registered voters says he would. That poll found Giuliani leading the former first lady 56 percent to 39 percent.

And to add to the appeal of a Senate race, Giuliani is still sitting with $2 million in his Senate campaign account from his aborted 2000 Senate race. That’s a small fraction of what he’d need, but it’s still a start.

Of course, there is one even stranger scenario out there for Giuliani. I’m not predicting it, but it’s worth mentioning.

Imagine that the economy doesn’t turn around as Republicans hope, or post-war Iraq continues to consume U.S. military personnel and dollars. If polls start to show Bush in real trouble for re-election, might Vice President Cheney decide that he could help the president by not running again? And if Cheney did that, would there be a better replacement than Giuliani, especially with the GOP convention in Madison Square Garden? It’s something to think about.

Stuart Rothenberg is editor of the Rothenberg Political Report.