Triumphant Biden takes aim at Sanders
Fresh off his first victory in the race for the US Democratic presidential nomination, Joe Biden has taken aim at frontrunner Bernie Sanders ahead of the contests dubbed "Super Tuesday".
Biden and four other Democratic contenders are set to help mark the anniversary of a landmark civil rights march in Alabama on Sunday.
A day earlier, strong support among African-American voters powered Biden to a resounding victory in South Carolina's nominating contest.
Alabama is one of 14 states holding contests on Tuesday in the race to pick a challenger to face Republican US President Donald Trump on November 3.
Biden, Michael Bloomberg, Pete Buttigieg, Elizabeth Warren and Amy Klobuchar will travel to Selma to commemorate the 55th anniversary of Bloody Sunday, when civil rights marchers were stopped and beaten by state troopers and local police while crossing a bridge.
Biden's South Carolina win on Saturday resurrected his struggling campaign in the state-by-state battle for the Democratic nomination.
The victory put the former vice president in position to claim he is a viable moderate alternative to self-described democratic socialist Sanders, an independent US senator from Vermont.
Sanders' strong performances in the first three contests in Iowa, New Hampshire and Nevada catapulted him to frontrunner status.
Biden said he believed Sanders would lead the Democratic Party to a big loss against Trump.
"I think Bernie Sanders' position on a number of the issues, even in the Democratic Party, are going to be - are very controversial," he told NBC's Meet the Press.
Americans, Biden said, are "not looking for a revolution, they're looking for results".
Biden won overwhelmingly in South Carolina, drawing 48 per cent of the votes cast compared to 20 per cent for Sanders.
Edison Research exit polls showed Biden with 61 per cent of African-American support in South Carolina to Sanders' 17 per cent.
Sanders planned to campaign on Sunday in heavily Democratic California, the biggest prize on Super Tuesday.
Meanwhile Biden reported raising $US5 million ($A7.7 million) in the past 24 hours.
Sanders leads in the overall national delegate count with 56 and Biden is second with 51, with another seven South Carolina delegates yet to be allocated.
A candidate will need at least 1991 delegates to win the nomination outright at the party's convention in July.
Australian Associated Press