Shortly thereafter Harris announced that she was seeking the Democratic presidential nomination in 2020. From the outset she was seen as one of the leading contenders, and she drew particular attention when, during a primary debate, she had a contentious exchange with fellow candidate Joe Biden over his opposition to school busing in the 1970s and ’80s, among other race-related topics. Although Harris’s support initially increased, by September 2019 her campaign was in serious trouble, and in December she dropped out of the race.