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There are roughly 8,000 Cuban migrants who have been stranded in Costa Rica, and they recently began a journey through Central America to cross into the U.S.

The Cuban issue could be especially tough for Rubio to navigate politically

Washington CNN  — 

Sen. Marco Rubio used the Cuban migrant crisis approaching U.S. borders on Thursday to lambast President Barack Obama’s policies toward Cuba as laughable.

The Cuban-American Republican senator from Florida was asked what he would do about Cuba as president on Thursday at an Americans for Peace, Prosperity and Security forum in New Hampshire.

He attacked Obama’s move to normalize relations with Cuba, saying the U.S. made “major concessions” and Cuba changed “nothing” in how they behave in return, including harboring fugitives, collaborating with U.S. enemies and oppressing its citizens.

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“Cuba oppresses its people so bad that today we have a migratory crisis from Cuba that’s being under-reported,” Rubio said. “You literally have thousands of Cuban migrants who have gone to Costa Rica and are now working their way up Central America to cross the U.S. border because once they come into the United States, they’re legal.”

There are roughly 8,000 Cuban migrants who have been stranded in Costa Rica, and they recently began a journey through Central America to cross into the U.S. at the southern border, with the first batch of dozens arriving over the weekend.

While Cuban migration to the U.S. has been steady for years, it has increased substantially since the Obama administration began to unfreeze relations with the Communist nation. Rumors and fears are rampant on the island that the change in policy will result in the repeal of the Cuban Adjustment Act, the 1960s legislation that gives Cuban immigrants special rights to stay in the U.S. and receive benefits if they make it to the country.

Rubio did not address how to stem the migration or what to do with the immigrants but harshly criticized the Cuban regime.

“That is the consequences of having a dictatorship 90 miles from our shores,” Rubio said. “They continue to send thousands and thousands and thousands of migrants toward the United States.”

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Regarding the thawing of relations, Rubio said nothing was changing in Cuba.

“What kind of one-sided deal is this?” he said. “No wonder why people around the world laugh at Barack Obama.”

The issue has yet to break through the presidential race news cycle, but is poised to do so. Securing the southern border and stemming illegal immigration is one of the most dominant conversation topics in the Republican primary. Hard-liners like Donald Trump and Sen. Ted Cruz, of Texas, have called for strict policies removing undocumented immigrants and building a wall along the border with Mexico.

The Cuban issue could be especially tough for Rubio to navigate: Born to Cuban immigrants, Rubio has often touted his closeness to immigration as an advantage in the race. He has also supported bipartisan immigration reform in the past that granted a pathway to citizenship to undocumented immigrants before changing course and advocating securing the border first.

Rubio has not called for reversing the policy allowing Cubans special immigration status to enter the country, but he has proposed legislation with other Cuban-American Florida lawmakers to curtail some of the benefits they receive unless they stay permanently in the U.S.

Other candidates have been slow to discuss the issue. Asked about the migrants in New Hampshire two weeks ago, former Florida Gov. Jeb Bush also turned the issue on Obama.

“They’re in a country that is a gulag and they’re leaving because they have no freedom, but this administration has rewarded that country with diplomatic relations and they’re fearful that they will have immigration rules applied to them like every other country where you have diplomatic relations,” Bush said. “That’s a pretty interesting signal about the failure of the Obama administration’s policy towards Cuba.”

CNN’s Ashley Killough contributed to this report.