Donald Trump Tweets That Cuban Leader Raul Castro Has 'No Respect' for President Obama

What 2016 GOP candidates are saying about Obama's trip to Cuba.

Obama is the first sitting U.S. president to visit the island nation in almost 90 years.

But Cruz argued in an op-ed published in Politico Sunday that “Obama has chosen to legitimize the corrupt and oppressive Castro regime with his presence on the island.”

Cruz’s father was a Cuban political prisoner who fought against the Fulgencio Batista regime in the 1950s and immigrated to the United States.

“I applaud President Obama for making history by traveling to Cuba and moving relations between our two countries into a new era,” Sanders wrote in statement released Sunday. “I continue to stand by his calls for Congress to fully lift the failed embargo.”

The Vermont senator added, “fifty years of cold war is enough. It is time for Cuba and the United States to turn the page and normalize relations.”