MIAMI — When Charlie Crist went to Miami’s Little Havana recently, the Democratic candidate for governor stood before a crowd and said what few politicians have in decades of scrounging for votes in the Cuban-American neighborhood: End the trade embargo against Cuba.

“If you really care about people on the island, we need to get rid of the embargo and let freedom reign,” he said, shouting above a small band of protesters who responded with chants of “Shame on you!”

Crist’s supporters cheered louder.

It was a scene inconceivable just a few years ago, when politicians were careful about what they said on the issue, for fear of alienating Cuban-American voters, many of whom fled Fidel Castro’s Cuba in the 1960s.

But Democrats now sense an opening with newer Cuban arrivals and second-generation Cuban-Americans who favor resuming diplomatic relations with the communist island.

In a sign of just how much the climate has shifted, Democrat Hillary Rodham Clinton, who backed trade limits when she ran for president in 2008, is now calling for the embargo to be lifted. She described it as “Castro’s best friend” and said it hampers “our broader agenda across Latin America.”

Her words mark the first time a leading presidential contender from either political party has suggested reversing the 52-year-old policy.

The efforts represent the largest challenge to Cuban-American orthodoxy in decades and could help reshape American foreign policy.

It also could alter the political landscape in the largest swing-voting state, where Republicans long have dominated the Cuban vote by taking a hard line on the embargo.

Crist’s campaign will be the first statewide test of whether the trade restrictions are still a live wire for politicians in Florida, home to 70 percent of the nation’s Cubans.

Crist is a former Republican governor who once said he would only visit Cuba “when it’s free.” Now that he’s a Democrat and trying to regain his old job, he has floated the idea of going to Havana “to learn from the people of Cuba and help find opportunities for Florida businesses.”

He argues that the embargo has failed because it has not toppled the Castro government but has hurt the Cuban people. “The definition of insanity is doing the same thing over and over again and expecting a different result,” he told reporters at the opening of a campaign office in Little Havana.

Florida Republicans are outraged, casting Crist’s position as a betrayal of the Cuban-American community.

“I’m going to stand with Cuban-Americans that believe in freedom, believe in democracy, believe in freedom of speech and oppose the oppression of Cuba,” said Republican Gov. Rick Scott. Crist, he added, will “be standing with Castro.”

U.S. Sen. Marco Rubio, a potential Republican presidential candidate whose parents left Cuba in the 1950s, said the embargo is “the last tool we have remaining to ensure that democracy returns to Cuba one day.”

Lifting the embargo, he said, would “further entrench the regime in power by giving them more money to carry out their violent repression of people’s fundamental rights and dignity.”