Why did Strom Thurmond begin to change with the times as various civil rights laws

Why did Strom Thurmond begin to change with the times as various civil rights laws were passed?
A filibuster by Thurmond's Democratic colleagues convinced him that the time
to change had come.
The economic power of African Americans and their influence on the state's
economy swayed Thurmond.
O A personal appeal by leaders of the movement for civil rights transformed
Thurmond's stance.
African Americans' ability to exercise their right to vote in South Carolina led to
Thurmond's change.