Democratic Party leaders are upping the pressure on Bernie Sanders to drop his presidential campaign, alarmed that his continued presence is undermining efforts to beat the presumptive Republican nominee, Donald Trump, and again win the White House.

Democratic US presidential hopefuls fighting for African-American voters have been seeking an edge in South Carolina as Republicans criss-crossed the state for a path out of Donald Trump's long shadow.

Before Hillary Clinton, 34 women have tried to become US president, including a daughter of Irish parents who ran 40 years ago, and a radical feminist in the 1870s, writes Bette Browne