Former US Secretary of State Hillary Clinton discusses "Smart Power: Security Through Inclusive Leadership" at Georgetown University in Washington, DC, December 3, 2014. AFP PHOTO / Jim WATSONJIM WATSON/AFP/Getty Images

President Obama's move to normalize relations with Cuba is almost certain to be supported by his former secretary of state, Hillary Rodham Clinton, who said earlier this year that  the half-century-old embargo was outdated and counterproductive.

She has also called the failure to win the release of prisoner Alan Gross, who was freed Wednesday, one of the regrets of her tenure.

Clinton, who is considering a Democratic bid for the White House, is at odds with Republican 2016 hopefuls such as Sen. Marco Rubio (Fla.) and former Florida Gov. Jeb Bush, who criticized Obama's Cuba moves on Wednesday. The Cuban-American population is a particularly crucial voting bloc in the battleground state of Florida.

Clinton was in charge of the State Department when Gross was arrested and imprisoned in 2009, and presided over secret and public efforts to being him home until she left the government in February 2013.

In her memoir "Hard Choices," released in June, Clinton blames the Cuban government.

"It is possible that hard liners within the regime exploited the Gross case as an opportunity to put the brakes on any possible rapprochement with the United States and the domestic reforms that would require," Clinton wrote. "If so, it is a double tragedy, cosigning millions of Cubans to a kind of continued imprisonment as well."

In interviews to promote the book, Clinton went further by pointedly criticizing the embargo as ineffective. Republicans accused her of flip-flopping on her earlier support for a tough line against the Cuban regime. Clinton's argument was that the embargo actually helped the Castro brothers, who rule the island nation, and had backfired. That was the same theme Obama articulated on Wednesday.

"Near the end of my tenure I recommended to President Obama that he take another look at our embargo," Clinton wrote in her book. "It wasn’t achieving its goals and it was holding back our broader agenda across Latin America. After twenty years of observing and dealing with the U.S.-Cuba relationship, I thought we should shift the onus onto the Castros to explain why they remained undemocratic and abusive."