The former mayor filed papers to create the Rudy Giuliani Presidential Exploratory Committee, Inc., establishing a New York-based panel that would allow him to raise money to explore a White House run and travel the country.
The four-page filing, obtained by The Associated Press, lists the purpose of the non-profit corporation "to conduct federal 'testing the waters' activity under the Federal Election Campaign Act for Rudy Giuliani."
The paperwork, dated last Friday, is signed by Bobby Burchfield, a partner at the DC-based law firm of McDermott Will & Emery, a firm that handles political work.
"Mayor Giuliani has not made a decision yet," Giuliani spokeswoman Sunny Mindel said in a statement Monday night. "With the filing of this document, we have taken the necessary legal steps so an organization can be put in place and money can be raised to explore a possible presidential run in 2008."
One potential rival for the Republican Party nomination, Sen. John McCain of Arizona, said Sunday he was taking the initial step of setting up an exploratory committee.
Under federal election law, an exploratory committee allows an individual to travel and gauge the level of support for a candidacy without formally declaring themselves a candidate and adhering to all the federal rules of fundraising. An individual who spends money only to test the waters — but not to campaign for office — does not have to register as a candidate under the election law.
The Republican field is expected to grow with Massachusetts Governor Mitt Romney, Sen. Bill Frist of Tennessee, Arkansas Gov. Mike Huckabee and New York Gov. George Pataki expected to join the presidential fray.
Democratic Gov. Tom Vilsack of Iowa has filed to establish a full-blown campaign committee and will make a more formal announcement of his candidacy later this month.
Giuliani was widely praised for leading the city during and after the terror attacks of Sept. 11, 2001. He has said for months that he would wait until the end of the 2006 elections to decide whether to embark on a White House bid.
The former mayor is a moderate who supports gun control, same-sex civil unions, embryonic stem-cell research and abortion rights — stands that would put him at odds with the majority of the Republican conservative base.
Giuliani has tried to sidestep those differences and offered strong praise for President George W. Bush at the 2004 Republican Party convention in New York.
"It doesn't matter what the media does to ridicule him or misinterpret him or defeat him. They ridiculed Winston Churchill. They belittled Ronald Reagan. But like President Bush, they were optimists. Leaders need to be optimists. Their vision is beyond the present, and it's set on a future of real peace and security," Giuliani said.
"Some call it stubbornness. I call it principled leadership."
In 2006, the Giuliani brand remained strong. He headlined fundraisers for Republican candidates nationwide and his travel has done little to deny 2008 ambitions. During a visit earlier this month to Columbia, South Carolina, Giuliani dodged the question: "There's a chance, but that's after this election is over."
He then left South Carolina for New Hampshire, site of the nation's first primary and another Republican fundraiser.
Giuliani enjoys strong name recognition and a recent AP-AOL News poll conducted in late October found that among Republicans Giuliani was essentially tied with Condoleezza Rice and McCain on who they would most like to see elected president in 2008.
Rice has insisted that she will not run.
Giuliani, who was in his final months as New York City mayor when a pair of planes crashed into the World Trade Center's towers, became a national hero. Within hours of the attack, the mayor was visiting the site, caked in dust and walking through the chaos — a moment replayed repeatedly on television.
Assuming the role of "America's Mayor" and Time Magazine's Person of the Year for 2001, Giuliani remained an in-demand speaker and Republican fundraiser. He was the first Republican to lead New York in decades, had cut crime and redeveloped rundown parts of the city.
He was a former U.S. attorney, leading campaigns against organized crime and corruption. He spent two years as the Justice Department's No. 3 post, overseeing all U.S. attorneys, the Drug Enforcement Agency and the U.S. Marshals Service. The Brooklyn native was first elected New York's mayor in 1993.
Giuliani eyed a run for the U.S. Senate in 2000, but ended that bid while battling prostate cancer and a made-for-tabloids divorce from television personality Donna Hanover. The messy divorce and his relationship with Judith Nathan also made his campaign against Hillary Rodham Clinton all the more difficult.
Long before the Sept. 11 attacks, the mayor cultivated a kind of celebrity status. He made a cameo on "Seinfeld" in 1993 and "Mad About You" the next year. He hosted Saturday Night Live in 1997 and followed up with other cameos. And in 2002, he was a presenter at MTV's Video Music Awards.