Trump compared to Hitler

Mexico City - Mexican ex-president Felipe Calderon tore into US Republican presidential hopeful Donald Trump on Saturday, comparing him to Adolf Hitler and blasting him as a racist. Calderon, a member of the conservative National Action Party (PAN), warned that Trump's rise in the Republican Party presidential primaries was fuelling anti-Americanism around the world.

Fellow conservative Trump's anti-migrant rhetoric is not aimed at all immigrants, but rather "he is talking about migrants that have a different colour than him – and that's frankly racist", said Calderon, speaking after an event in downtown Mexico City.

Trump is exploiting the social fears "that in his time Hitler himself did," Calderon said. He warned that Trump "is turning the United States into a neighbour that we're all going to end up rejecting and hating," and that was not in the best interest of the United States.

Mexico is the third most important US trade partner after Canada and China, and the neighbours share a 3,145km border. Trump angered Mexico by declaring that the country was sending rapists and murderers across the border, and that he would force Mexico to pay for a giant wall to keep illegal migrants out.

Earlier in the month, Calderon - who served as president from 2006 to 2012 - dismissed the idea of building a border wall as "stupid."

Another conservative Mexican ex-president, Vicente Fox (2000-2005), said that Trump was "crazy" and recently told the US television network Fusion: "I'm not going to pay for that fu***ng wall."

US Vice President Joe Biden, speaking Thursday during a visit to Mexico, said the message expressed about Mexicans by some candidates in the US election campaign is "dangerous, damaging and incredibly ill-advised," but that this episode of "xenophobia" will pass.

President Enrique Pena Nieto's administration has called Trump's comments about Mexicans "prejudiced and absurd".

Meanwhile, Hillary Clinton scored a resounding victory against Bernie Sanders in Saturday's Democratic primary in South Carolina, seizing momentum ahead of the most important day of the nomination race: this week's "Super Tuesday" showdown.

Four weeks into the White House primaries, the former secretary of state earned her first decisive win of the campaign, after a nail-biter victory in Iowa, a thumping loss to Sanders in New Hampshire, and then a five-point win in Nevada.

South Carolina was the first southern state to vote for a 2016 Democratic nominee, before the race broadens to 11 contests across the country.

"Tomorrow this campaign goes national," Clinton said to a loud roar as she thanked supporters in Columbia, South Carolina, where she emerged with a clearer path to the nomination.

"We're going to compete for every vote in every state. We're not taking anything, and we're not taking anyone, for granted."

US networks called the race for Clinton immediately after polls closed in the Palmetto State, where the majority of Democratic voters are African-American, a voting bloc that she and her husband, former president Bill Clinton, have successfully courted for decades.

Clinton also looked beyond her battle with Sanders, tweaking the man many now see as the likely Republican nominee: Donald Trump, whose campaign slogan is "Make America Great Again."

"Despite what you hear, we don't need to make America great again. America has never stopped being great," she said, reading off a teleprompter.

"But we do need to make America whole again," she added, laying out an argument against the divisive rhetoric favoured by Trump, who has antagonised immigrants, Muslims and campaign rivals.

With 99 percent of precincts reporting, Clinton stood at 73.5 percent compared to 26 percent for Sanders.