ATLANTA -- Black voters expressed a mix of hope and worry Monday over Joe Biden’s exit from the presidential race and the prospect of Vice President Kamala Harris becoming the Democratic nominee. A key Democratic constituency, Black voters helped power Biden to victory in the 2020 primaries and ultimately to the White House, and they were among his most steadfast supporters, even as calls for him to quit grew. But as much pride as some Black Americans feel about the possibility of Harris, who is of Black and Indian descent, becoming president, the upending of the race has some voters...