Peters noted that a Florida-based student debate organization, USA Youth Debates, recently obtained a license from the Treasury Department to allow American students into Cuba early next year.

A five-day trade mission to Cuba by New Mexico Gov. Bill Richardson that wrapped up on Friday renewed speculation about the administration's intentions. After Obama eased the restriction on exiles traveling to the island -- and gave U.S. telecom firms wide latitude to do business on the island, Cuba permitting -- he said the next move is Cuba's.

``We think it's important to see progress on issues of political liberalization, freedom of the press, freedom of assembly, release of political prisoners in order for there to be the full possibility of normalization between our two countries,'' he said in a July interview.

From all outward indications, he's still waiting.

Richardson, a supporter of increased travel to Cuba, called the current atmosphere ``the best I've seen for an improvement'' in U.S.-Cuba ties.

``What is needed is concrete steps from both sides,'' said the diplomatic troubleshooter, who did not meet with either Fidel or Raúl Castro but did talk with Ricardo Alarcón, head of Cuba's parliament.

Richardson said he would present a report about his visit to the Obama administration.

The recent resignation of Florida Sen. Mel Martinez, an influential Republican, staunch supporter of the embargo and one of two Cuban Americans in the Senate, was a political blow to the pro-embargo forces. On Friday, Gov. Charlie Crist appointed his former chief of staff, George LeMieux, to keep the seat warm until Crist himself can run in 2010.

Crist and other leading contenders for Martinez's seat -- Republican former House Speaker Marco Rubio and Democrat Rep. Kendrick Meek -- advocate keeping the embargo intact.

Lost in the argument over what the United States might do is the fact that change is a two-way street. Cuba can say thank you, but no, we don't want to do business with you.

``What the Cuban government wants is more American tourists,'' said Mauricio Claver-Carone, board member with the politically influential U.S.-Cuba Democracy PAC, a pro-embargo group that contributed $452,000 to Democrats and $308,500 to Republicans in 2008. ``It's an easy source of financing, and they control that commodity.''

What the Cubans don't want is a flood of American fast-food franchises, particularly ones run by Cuban exiles. Over the years, Fidel Castro has railed against the embargo -- called a blockade on the island -- whenever he needed to deflect blame for the island's chronic shortages.

LAWMAKERS DIVIDED

If Obama were to announce he was lifting the embargo immediately, ``Fidel would sink an American ship or shoot down a plane, or do whatever he could to stop it,'' said attorney Pedro Freyre, who represents companies with licenses to do business in Cuba.

That won't be necessary if U.S. Rep. Ileana Ros-Lehtinen and her fellow Republican lawmaker, Lincoln Diaz-Balart, have their way. Diaz-Balart pushed successfully to give Congress, not the White House, final say over the policy. And Ros-Lehtinen's position as top Republican on the House Foreign Affairs committee is a strategic perch.

Both lawmakers expected a fight over travel to Cuba in mid-July when Congress took up the annual spending bill for the U.S. Treasury Department. Because it provides funding to enforce sanctions, the bill has traditionally served as the vehicle for trying to undermine the policy.

That fight never materialized.

``We were prepared,'' Lincoln Diaz-Balart said. ``No matter how much they (embargo critics) talk, no matter how many press conferences they hold, the bottom line is they don't have the votes.''

Some of those who support lifting the travel ban say they're girding for a more significant victory when Congress returns from its August recess.

Rep. Jeff Flake, an Arizona Republican who has long argued that the United States shouldn't dictate where Americans can travel, said he and his allies want to push the proposal on its own, not as an amendment in the larger Treasury bill.

``It's a reflection of greater confidence that we believe we can do more,'' Flake said. ``We'd rather win on the merits.''

But it is unclear how much enthusiasm congressional leaders will have for a bruising battle over Cuba when they have yet to close the deal on such contentious Obama administration priorities as healthcare reform and climate change.

Rep. Bill Delahunt, a Massachusetts Democrat and critic of the embargo, believes his side has the stomach and win.

``You have an administration that wants to engage,'' he said. ``The pieces are coming together.''

Ros-Lehtinen acknowledges increased interest, but says advocates of a thaw are dreaming if they think they can undo the half-century-old policy.

``When have they not been for lifting the embargo, the travel ban? When have they not said, `This is the year'?''

Miami Herald staff writers Alfonso Chardy, Jim Wyss and Frances Robles and The Associated Press contributed to this report.