Backlash after Obama shakes hands with 'murderer' Raul Castro Obama greeted a long line of world leaders and heads of state in Johannesburg as thousands gathered to remember Mandela at the FNB World Cup stadium Sen. Marco Rubio, who hails from a Cuban emigre family, said Obama should have asked Castro 'him about those basic freedoms Mandela was associated with that are denied in Cuba' One South Florida congresswoman told a TV audience that the handshake was 'nauseating ... He shook the hand of a murderer, of a thug. And those are bloodied hands The US President shook hands Cuban leader Raul Castro and then Brazilian President Dilma Rousseff, who has clashed with Obama over alleged National Security Agency spying Obama used his eulogy to criticize dictators who only pay 'lip service' to Mandela's human-rights legacy The crowd repeatedly booed South African president Jacob Zuma but cheered Obama and dictator Robert Mugabe By Louise Boyle and David Martosko, U.s. Barack Obama shook hands with Cuban President Raul Castro today, an unprecedented gesture of friendship which occurred, fittingly, at the memorial service for Nelson Mandela - but left the U.S. president facing backlash that he had warmly greeted a 'murderer'. The handshake between leaders of the two Cold War enemies took place during a ceremony which honored the former South African President's powerful legacy of reconciliation. But members of the U.S. Congress were upset on Tuesday, led by Florida Republican Senator Marco Rubio, a Florida Republican and son of Cuban immigrants. 'If the president was going to shake his hand, Rubio told MailOnline, 'he should have asked him about those basic freedoms Mandela was associated with that are denied in Cuba.' Rubio has been an outspoken critic of the Castro regime which he said earlier this year 'sponsors terrorism abroad and against their own people.' It is nauseating, Florida GOP congresswoman Ileana Ros-Lehtinen told Fox News. I was born in Cuba, had to leave the homeland because of oppression... And those are bloodied hands. 'If it's just a handshake that's not going to produce any change, I think Raul Castro should have listened to what Obama said' about human rights, she insisted. President Barack Obama shakes hands with Cuban President Raul Castro during the official memorial service for former South African President Nelson Mandela in Johannesburg today Historic: The handshake between Obama and Fidel Castro's brother Raul came during a ceremony that focused on Mandela's legacy of reconciliation. Brazilian President Dilma Rousseff looks on during the historic moment Obama waves as he arrives to speak to crowds attending the memorial service for former South African president Nelson Mandela at the FNB Stadium in Soweto near Johannesburg Obama greets Cuban President Raul Castro before giving his speech at the memorial service, an unprecedented gesture between the leaders of two nations which have been at loggerheads for more than half a century The gesture seemed to show another small step toward rapprochement between the U.S. and Cuba, raising hopes the two nations could be on the verge of a breakthrough in relations. But Ros-Lehtinen, who represents thousands of Cuban refugees who are now U.S. citizens, was so upset that she laid into Secretary of State John Kerry during an unrelated hearing about Iran. 'When the leader of the free world shakes the bloody hand of a ruthless dictator like Raul Castro, it becomes a propaganda coup for the tyrant,' she lectured him before the House Foreign Affairs Committee. Raul Castro uses that hand to sign the orders to repress and jail Democracy advocates. In fact, right now as we speak Cuban opposition leaders are being detained and they're being beaten while trying to commemorate today, which is International Human Rights Day.' Kerry deflected the criticism. Today is about honoring Nelson Mandela. And the president is at an international funeral ... he didn't choose who's there,' he said. Ros-Lehtinen asked if Castro is honoring the human rights of Cubans. 'No, absolutely not,' Kerry replied. Former US president Jimmy Carter (left), pictured with former UN Secretary General Kofi Annan and UN and Arab League mediator Lakhdar Brahimi at Mandela's memorial today, said Obama's handshake with Raul Castro was 'significant' and he hoped it would be an omen for the future Former president Jimmy Carter, who was part of the U.S. delegation to attend Mandela's memorial, said that the handshake was 'significant', adding: 'I hope that will be an omen for the future.' The handshake between Obama and the brother who took over the duties of longtime Cuban dictator Fidel Castro was seen by millions around the world on live television. A White House official said it was not 'pre-planned'. The Cuban government hailed it as a hopeful sign, writing on its website: 'May this... be the beginning of the end of the US aggressions.' Obama later used his eulogy to Mandela, a man he considers a personal hero, to address dictators of the world who pay lip service to Mandela's legacy while repressing their own people. He said: 'There are too many of us who happily embrace Madiba's legacy of racial reconciliation, but passionately resist even modest reforms that would challenge chronic poverty and growing inequality. 'There are too many leaders who claim solidarity with Madiba's struggle for freedom, but do not tolerate dissent from their own people. And there are too many of us who stand on the sidelines, comfortable in complacency or cynicism when our voices must be heard. A group of U.S. lawmakers visited with Castro in February, in a failed bid to secure the release of U.S. government contractor Alan Gross, who has been imprisoned there since December 2009. Gross was sentenced to 15 years in prison for installing Internet networks as part of a secretive U.S. program that aids dissidents in connecting with the outside world. Small steps: Cuban President Raul Castro Ruz, right, watches President Obama following his speech at the memorial service Obama and British Prime Minister David Cameron pose for a selfie photo with Denmark's Prime Minister Helle Thorning Schmidt (center) as First Lady Michelle watches the memorial service Vermont Democratic Sen. Patrick Leahy led the delegation, which also included Republican Senator Jeff Flake of Arizona; Democratic Senators Debbie Stabenow of Michigan, Sherrod Brown of Ohio, and Sheldon Whitehouse of Rhode Island; and Democratic Representatives Jim McGovern of Massachusetts and Chris Van Hollen of Maryland. The Obama administration has made Gross" release a condition of any future thaw in America's icy relationship with Havana. Under the 1996 'Helms-Burton' law, U.S. trade sanctions with Cuba cannot be lifted until the nation's one-party Communist political system gives way to another form of government. At Tuesday's memorial service, Obama greeted a long line of world leaders and heads of state attending the memorial service in Johannesburg after flying to South Africa with a U.S. delegation which included former presidents Bill Clinton, George W Bush and Jimmy Carter along with their families. Obama also shook hands with Brazilian President Dilma Rousseff, who has clashed with the U.S. President over alleged National Security Agency spying. He was later spotted in the VIP stands posing for a 'selfie' camera phone picture with British Prime Minister David Cameron and Danish PM Helle Thorning Schmidt. Obama arrived an hour late to the memorial service on Tuesday after missing the opening speeches when his motorcade got stuck in traffic. The President was greeted with a rapturous ovation when he arrived at the FNB Stadium to pay tribute to the former South African leader. Obama described Mr Mandela as the 'last great liberator of the 20th century' and compared him to Ghandi and Martin Luther King in a powerful address to the crowds. President Barrack Obama greets the crowd who stood for hours in torrential rain to say goodbye to their beloved Madiba Obama opened his speech by thanking Mandela's family, then continued: 'To the people of South Africa - people of every race and walk of life - the world thanks you for sharing Nelson Mandela with us. 'Mandela taught us the power of action, but also ideas; the importance of reason and arguments; the need to study not only those you agree with, but those who you don't.' Referring to the anti-apartheid icon's friendship with his own prison warders, the President said: 'It took a man like Madiba to free not just the prisoner, but the gaoler as well.' To the people of South Africa - people of every race and walk of life - the world thanks you for sharing Nelson Mandela with us. Born during World War I, far from the corridors of power, a boy raised herding cattle and tutored by elders of his Thembu tribe - Madiba would emerge as the last great liberator of the 20th century. He was not a bust made of marble; he was a man of flesh and blood - a son and husband, a father and a friend. Mandela showed us the power of action; of taking risks on behalf of our ideals. Mandela understood the ties that bind the human spirit. There is a word in South Africa - 'Ubuntu' - that describes his greatest gift: his recognition that we are all bound together in ways that can be invisible to the eye; that there is a oneness to humanity; that we achieve ourselves by sharing ourselves with others, and caring for those around us. It took a man like Madiba to free not just the prisoner, but the gaoler as well; to show that you must trust others so that they may trust you; to teach that reconciliation is not a matter of ignoring a cruel past, but a means of confronting it with inclusion, generosity and truth. He changed laws, but also hearts. There are too many of us who happily embrace Madiba's legacy of racial reconciliation, but passionately resist even modest reforms that would challenge chronic poverty and growing inequality. There are too many leaders who claim solidarity with Madiba's struggle for freedom, but do not tolerate dissent from their own people. We will never see the likes of Nelson Mandela again. But let me say to the young people of Africa, and young people around the world - you can make his life's work your own. Over thirty years ago, while still a student, I learned of Mandela and the struggles in this land. It stirred something in me. It woke me up to my responsibilities - to others, and to myself - and set me on an improbable journey that finds me here today. And while I will always fall short of Madiba's example, he makes me want to be better.