In this Feb. 26, 2016, file photo, Republican presidential candidate Donald Trump gestures during a speech at a rally in Oklahoma City. Democrats increasingly view Trump as the likely Republican nominee and are seeking consensus on the best way to challenge the billionaire鈥檚 unpredictable appeal in a general election. AP
WASHINGTON, United States 鈥� Conservatives and liberals alike rounded on Republican Donald Trump for refusing to reject on Sunday an endorsement by David Duke, a white nationalist who once led the Ku Klux Klan.
Among Democrats, Hillary Clinton sailed toward the 鈥淪uper Tuesday鈥� primaries bolstered by a blowout win in South Carolina on Saturday.
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With just two days to go before the biggest showdown yet in the US presidential race, Clinton gained crucial momentum in the race for the Democratic nomination by crushing rival Bernie Sanders 73.5 to 26 percent.
鈥淲e got decimated,鈥� Sanders conceded in an interview on ABC鈥檚 鈥淭his Week鈥� show, acknowledging that the outpouring of African American support for Clinton exposed a weakness in his campaign.
On the Republican side, Trump鈥檚 trailing rivals desperately tried to raise doubts among voters about the frontrunner鈥檚 ability to beat Clinton in the November 8 presidential election.
Senator Ted Cruz suggested in an interview with ABC鈥檚 鈥淭his Week鈥� show that Mafia dealings could be hiding in Trump鈥檚 tax returns, which the billionaire real estate developer has so far resisted releasing.
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Trump said he knew nothing about KKK leader Duke when asked about the matter on CNN鈥檚 鈥淪tate of the Union鈥� talk show.
鈥淚 don鈥檛 know what group you鈥檙e talking about. You wouldn鈥檛 want me to condemn a group that I know nothing about. I鈥檇 have to look,鈥� Trump said.
On Friday, he had appeared surprised when asked about the issue at a press conference, and quickly said: 鈥淚 disavow.鈥�
His comments Sunday on CNN however drew prompt criticism from across the political spectrum.
鈥淲e cannot be a party that nominates someone that refuses to condemn white supremacists and the Ku Klux Klan,鈥� Senator Marco Rubio told a crowd of supporters in Virginia.
鈥淣ot only is that wrong, it makes him unelectable.鈥�
Another rival, Ohio Governor John Kasich, tweeted: 鈥淗ate groups have no place in America. We are stronger together. End of story.鈥�
Cruz deplored the 鈥渞eally sad鈥� comments. 鈥淍realDonaldTrump you鈥檙e better than this. We should all agree, racism is wrong, KKK is abhorrent,鈥� he wrote.
Conservative media baron Rupert Murdoch urged Republicans to 鈥渃ool it and close ranks to fight real enemy.鈥�
Sanders, a self-declared democratic socialist, wrote: 鈥淎merica鈥檚 first black president cannot and will not be succeeded by a hatemonger who refuses to condemn the KKK.鈥�
In a rare sign of agreement between the rivals, Clinton retweeted Sanders鈥檚 comment.
Last year, a technology blog unearthed a 1927 news report stating that Fred Trump 鈥� Donald Trump鈥檚 father 鈥� was one of seven men arrested during clashes between 1,000 KKK members and 100 police officers in Queens, New York.
Trump has denied that 鈥渞idiculous鈥� report, telling the Daily Mail, a British newspaper: 鈥淗e was never arrested. He has nothing to do with this. This never happened. This is nonsense and it never happened.鈥�
Trump鈥檚 tax returns
Trump has said he will not release his tax returns because they are being audited by the Internal Revenue Service.
鈥淵ou can鈥檛 tell anything from tax returns because you take deductions, massive deductions and lots of other things,鈥� he said on CNN.
Polls show Trump, who on Friday was endorsed by New Jersey Governor Chris Christie, leading the Republican pack in most of the 11 Super Tuesday contests.
Trump however trails Cruz in the senator鈥檚 home state of Texas, a top Super Tuesday prize with 155 delegates.
The conventional wisdom is that Trump鈥檚 rivals 鈥� Cruz, Kasich and Florida Senator Marco Rubio 鈥� must at least win their own states to remain in the running. Cruz will be the first to face that test, as Florida and Ohio vote later.
鈥淭here is no doubt that if Donald steamrolls through Super Tuesday, wins everywhere with big margins, that he may well be unstoppable,鈥� Cruz acknowledged on CBS鈥檚 鈥淔ace the Nation.鈥�
Kasich predicted that Trump would probably win all the Super Tuesday contests, but the governor said he intended to hang on in hopes Cruz and Rubio are knocked out first.
Retired neurosurgeon Ben Carson also has vowed to remain in the race, but support for his candidacy has fizzled.
With the stakes nearing a make-or-break point, Trump, Cruz and Rubio have viciously attacked each other with taunts, accusations and angry tweets that have given the Republican race a distinctly Darwinian flavor.
Redemption
While the Republicans were hitting all the political talk shows Sunday, Hillary Clinton was quietly savoring her victory in South Carolina.
It was the former secretary of state鈥檚 first decisive win of the campaign,聽after a nail-biter victory in Iowa, a thumping loss to Sanders in New Hampshire and a five-point win in Nevada.
Exit polls in South Carolina showed African-Americans 鈥� who represented 61 percent of all Democratic voters in that state鈥檚 primary 鈥� backed Clinton by 86 percent, more than had supported Obama eight years prior.
Clinton, who leads in the national delegate count, assiduously courted black voters, partly by praising Obama and promising to build on his legacy.
The 11 states holding Democratic nominating contests Tuesday will send 18 percent of the delegates to July鈥檚 nominating convention in Philadelphia.