And the reason was clear in Hialeah, where the prosecutor-turned-politician was introduced by Miami-Dade County Commissioner Rebeca Sosa as the man who healed the wounds of 9/11 and stood up to Castro, telling him, "Usted es una persona non grata en Nueva York!"
It was a story they already knew by heart, and the candidate repeated it on this day for good measure: In 1995, during the 50th anniversary of the United Nations, Giuliani forbade Castro to attend a banquet of world leaders.
"Castro is a murderer," Giuliani boomed through La Carreta's packed banquet hall. "I know it. I will never forget. So is his brother. I know it. I will never forget it."
Others might "romanticize" Castro and his ilk, but Cuban Americans know better than anyone else, he said, how important it is "to be strong in the face of dictators and terrorists . America can't show weaknesses to these Islamic terrorists. Because, if we do, we're going to be in a lot greater danger."
Giuliani has probably visited Florida more than any other state since confirming in February that he would seek the Republican nomination for president. The state gave the White House to Bush in 2000. ("Thank God!" he told his Hialeah audience.) And it will be key again in 2008, he said, both in its January primary and in November.
Most primary candidates tend to focus scarce resources on a small handful of early voting states. They will practically take up residence in, say, Iowa or New Hampshire, and pull 16-hour days with half a dozen public events in as many cities.
But Giuliani's public schedule generally holds to a more regal pace; it is the luxury of being national front-runner. Giuliani often has just one public campaign event per day, although he often schedules multiple private fundraisers. In the last four months, he has visited at least 21 states. He plans to be in Sacramento today and Irvine on Friday.
National campaign manager Michael DuHaime acknowledges that Giuliani hasn't "done the 14 stops in three days in Iowa yet" but insists that the candidate keeps to "an incredibly fast pace" and is serious about Iowa and all of the early voting states.
"But the reality is, no one's ever run this race before," DuHaime said in an interview. "We haven't had a Republican presidential primary since Sept. 11. The old way of doing things has to be rethought."
If 9/11 really did change politics as usual, then there was no better place for Giuliani to be Friday than the North Charleston Coliseum, where the region remembered "our nine heroes," firefighters killed while battling a furniture store blaze.
Giuliani was supposed to fly from South Florida to Jacksonville, Fla., for a town hall meeting at a junior college.
But then the campaign got a call from Lewis Hayes, chairman of South Carolina Firefighters for Rudy, inviting the candidate to the memorial service.
So Jacksonville was out, and the candidate flew north to pay his respects. His staff stressed that the trip was just that, not an official campaign event.
Giuliani wasn't the only man who stepped off the trail Friday. Republican Mike Huckabee and Democrats Joseph R. Biden Jr., Christopher J. Dodd and John Edwards were all present. Hillary Rodham Clinton and Barack Obama had called Charleston Mayor Joseph P. Riley Jr. to express their sympathy.
However, Giuliani is the only one who has written a book on leadership with a chapter called "Weddings Discretionary, Funerals Mandatory." The only one whose city lost 343 firefighters and 60 police officers on one horrible day in 2001.
He's the only one who inspires both wrath and respect in firefighters for his actions in response to Sept. 11.
And he is the only one who can sit in a cavernous auditorium amid thousands of uniformed first responders and give a campaign speech without saying a word.