REUTERS/Rick WilkingMANCHESTER, N.H. (Reuters) - Bernie Sanders was due to have breakfast with one of America's most prominent civil rights activists, Al Sharpton, just hours after trouncing Hillary Clinton in the New Hampshire Democratic presidential nominating contest. The meeting marks a recognition by Sanders that his campaign must swiftly broaden its base of support if he has any chance of mounting a long-term challenge to Clinton, who consistently polls better among African American voters. They will play a crucial role in the Democratic race as it moves to South Carolina - where more than half of the Democratic primary voters in 2008 were African American - and other states more diverse than New Hampshire or Iowa, which held the first contest of the 2016 election. Sanders will meet with Sharpton in the same Harlem restaurant where the activist met with Barack Obama during his 2008 presidential campaign - an obvious bit of symbolism for the Vermont senator trying to connect with minority voters. There was no immediate comment from Sharpton on the breakfast. Even before the exit polls showing that Sanders had won New Hampshire, Clinton's campaign was already trying to highlight her double-digit lead over Sanders among African American and Latino voters. "It will be very difficult, if not impossible, for a Democrat to win the nomination without strong levels of support among African American and Hispanic voters," Clinton campaign manager Robby Mook said in a memo sent to reporters. He predicted the Democratic race would be won in March, when it quickly expands to 22 delegate-rich states with some of the largest minority and urban populations -- and that Clinton would have the advantage. Clinton has a long history of support for civil rights, and she has benefited from her husband Bill Clinton’s popularity in the black community during his presidency, although that became strained during the fierce 2008 primary battle with Obama. Reuters/Ipsos polling nationally showed that in January, blacks backed Clinton by a margin of 3 to 1 over Sanders.