An odd confluence of efforts at migration reforms in Washington and Havana has sparked calls for a review of the Cuban Adjustment Act — the U.S. law that has provided the greatest benefits to Cuban arrivals for the last half century.

Sen. Marco Rubio and Reps. Ileana Ros-Lehtinen and Mario Diaz-Balart, all South Florida Republicans and Cuban-Americans, say the CAA needs tweaking to stop abuses by those who “fled communism” and yet return repeatedly to the island.

And while the Obama administration and Democrats in Congress appear determined to keep the law intact, some advocates of improved U.S.-Cuba relations are calling for its total elimination as a Cold War leftover that gives Cubans benefits not available to any other migrants.

Under debate are whether Cubans are escaping repression or are economic migrants, the letter and spirit of the CAA and whether new arrivals still need the benefits of a 47-year-old law that fast tracks U.S. residency after just one year and one day.

Those questions burgeoned after reforms to Havana’s migration system on Jan. 14 created the possibility that more Cubans would be arriving in the United States, obtaining U.S. residency and then returning to the island quickly enough to retain their residency there.

The Obama administration had already lifted virtually all restrictions on Cuban-American travel to the island for family reunification visits. Washington also guarantees a minimum of 20,000 visas to Cubans per year — an assurance not available to any other country — under a 1994 bilateral agreement designed to discourage illegal and risky attempts to escape the island by sea.

The CAA, which was approved in 1966, was designed to normalize the status of about 123,000 Cubans who had fled Fidel Castro’s revolution and been “paroled” into the United States but were in immigration limbo. Well over 1 million Cubans have now obtained U.S. residency under the law, officially named the Cuban Refugee Adjustment Act.

Rubio has said that he and other senators now negotiating a U.S. migration reform package might not “be able to avoid, as part of a comprehensive approach to immigration, a conversation about the Cuban Adjustment Act.”

“It’s becoming increasingly difficult to justify it for my colleagues when there are people who come to the United States … and within a year and a day are traveling to Cuba 25 and 30 times a year” Rubio told journalists recently. “That being said, it’s important for us to remind people that Cuba is a tyrannical regime.”

U.S. immigration rights activists have long criticized the CAA — and the wet-foot, dry-foot policy that allows those who set foot on U.S. territory to remain while those intercepted at sea are sent back to Cuba. They point out that the law does not mention the words communism or persecution, and that it offers the benefits of refugee status, including public health, that would be better afforded to true refugees.

“A generous immigration system depends on fairness and even treatment across groups and no political favoritism. Economic migrants from Cuba should be treated the same as those from any other country,” said Phil Peters, a vice president of the Lexington Institute think-tank in Washington who recently wrote a hefty report on U.S.-Cuba migration issues.