For Mayor Giuliani, the prospect of running against Hillary Clinton is “déjà vu all over again.” The diehard Yankees fan turned to the classic line from Bronx Bomber legend Yogi Berra as he faced questions about his presidential ambitions yesterday in Greenwich Village. Mr. Giuliani had geared up to battle Mrs. Clinton for New York’s open Senate seat in 2000 before he dropped out to receive treatment for prostate cancer.

Now, as the Republican former mayor and the Democratic senator eye their party’s nominations, a rematch of the aborted 2000 race looms in 2008. But that’s a long way off, Mr. Giuliani said, adding that he had to worry more about his potential Republican opponents than those on the Democratic side.

“You have to think about them,” Mr. Giuliani said. “Can you win? Can you do a better job than they can do? Can you raise as much money or a competitive amount of money? Can you put together as good an organization?”

Mr. Giuliani has formed a federal exploratory committee, but he has not made a final determination about whether to run. He said yesterday he had “no idea what the timeframe will be” for a decision. “The people that talk to me are very, very encouraging,” he said. However, he quickly added: “But of course, generally the people that don’t want you to run don’t come up to you and tell you that. So you’ve got to be careful.”

He made no mention of his possible GOP opponents, which could include Senator McCain and Governor Romney of Massachusetts.

The former mayor on Tuesday announced that he had hired a former top official for President Bush’s re-election campaign, Sandra Pack, to serve as chief financial officer for his committee. And he is holding his first presidential fundraiser in New York on December 19.

Mr. Giuliani was in town yesterday to help Circuit City and the Fire Department launch a nationwide campaign honoring firefighters and promote the company’s in-home computer service. Along with Fire Commissioner Nicholas Scoppetta, Mr. Giuliani accepted checks — each worth $100,000 — on behalf of the FDNY Foundation and a charity for the children of firefighters. The Circuit City campaign includes an essay contest for Americans to nominate their local firehouses to receive thousands of dollars in donations from the company.