Speaking at Florida International University in Miami Friday, Hillary Clinton called on Congress to end the trade embargo the U.S. has imposed against Cuba since 1962.

The position, which Clinton already outlined in her 2014 book "Hard Choices," puts her in line with President Barack Obama, who moved in December to establish diplomatic relations with Cuba and has called for normalized trade relations.

Perhaps more importantly, it draws a sharp contrast with two top Republican presidential contenders from Florida, Sen. Marco Rubio and former Gov. Jeb Bush, at a time when younger Cuban-American voters in Florida are softening their stance on the matter. The Republican-led Congress is unlikely to allow such a change in U.S.-Cuba relations anytime soon.

"The Cuba embargo needs to go, once and for all," Clinton will say, according to excerpts released by her campaign. "We should replace it with a smarter approach that empowers the Cuban private sector, Cuban civil society, and the Cuban-American community to spur progress and keep pressure on the regime."

Clinton's campaign says she will frame her GOP rivals as backing "failed policies of the past."

She also plans to mention Republican leaders on Capitol Hill by name.

"Today I am calling on Speaker (John) Boehner and Senator (Mitch) McConnell to step up and answer the pleas of the Cuban people," she will say, according to the excerpts. "They want to buy our goods, read our books, surf our web, and learn from our people. They want to bring their country into the 21st century. That is the road toward democracy and dignity. We should walk it together."

U.S.-Cuba relations have long been a flashpoint in Florida politics. The generations of Cuban-Americans who were born in Cuba and fled shortly after the Castro-led revolution in the late 1950s generally supported a hard line, including the embargo that keeps American businesses from trading with Cuba and blocks Americans from traveling in the country and spending money there as tourists.

For decades, south Florida politicians and presidential candidates vying for the state's crucial electoral votes reflected those views, regardless of party. Clinton's husband was among them, even as he quietly attempted to engage Fidel Castro in the 1990s.

Now, says Florida pollster Fernand Amandi, an expert on Cuban-American public opinion, that once-solid voting bloc is "a community in transition," giving Clinton an opening that "wouldn't have been possible not very long ago."

U.S.-born Cuban-Americans, Amandi said, are consistently more supportive of normalized relations than their Cuban-born parents or, even if they aren't, the younger voters are less likely to consider themselves one-issue voters. "The younger generations are more like any other immigrants - they care about pocketbook issues, jobs, their kids' educations," he said.

There also has been an influx of Cuba-born immigrants in the last few decades, Amandi explained. "They lived under the sanctions and concluded that it just emboldened the Castro regime," he said. "So think after 55 years of failure, it's time for something else."

Beyond the Cuban-American community, a majority of adults in the U.S. support normalizing relations with Cuba. A Pew Research Center survey conducted July 14-20 found that nearly 73 percent of Americans approve of establishing diplomatic relations with Cuba while 72 percent support ending the trade embargo, both double-digit percentage increases from January, immediately after Obama's decision.

Pew found the same trends even among Republicans, with 56 percent of GOP voters backing a diplomatic bond and 59 percent supporting an economic relationship.

Rubio, whose parents emigrated from Cuba, remained unmoved Thursday, releasing a statement ahead of Clinton's visit. "Unilateral concessions to the Castros will only strengthen a brutal, anti-American regime 90 miles from our shore," Rubio said. "President Obama and Secretary Clinton must learn that appeasement only emboldens dictators and repressive governments, and weakens America's global standing in the 21st century.