Final answer:
Kamala Harris's role before being nominated for Vice-President was a prominent presidential candidate in the 2020 primary election.
Step-by-step explanation:
Kamala Harris's role before being nominated for Vice-President was a prominent presidential candidate in her own right during the 2020 primary election. She was asked by then-candidate Joe Biden to be his running mate in order to secure his electoral victory. Harris broke significant barriers by becoming the first woman and first person of Black and South Asian descent to be elected vice president of the United States.