WASHINGTON (AP) – A generation gap among black voters could be critical for Hillary Clinton and Bernie Sanders on Super Tuesday.

Older black voters, a reliable primary voting bloc, are coalescing around Clinton. Millennial black voters appear torn between the former secretary of state and her opponent, Bernie Sanders.

For Sanders to have any hope of overall success with black voters, who overwhelmingly supported President Barack Obama in 2008 and 2012, he’s going to have to not only win motivated young black voters, but persuade older voters who’ve supported the Clintons for years to defect to him.

Those voters helped Clinton win the South Carolina Democratic primary handily with 8 in 10 voting for her, and are expected to make a difference for Clinton throughout the South.