Why was the white primary so effective at preventing minorities from exercising their right to vote?

Question

Quizplus · Accepted Answer

The white primary was effective at preventing minorities from exercising their right to vote because it allowed only white Democrats to participate in the primary elections, which virtually always nominated white candidates who went on to win the general elections in the South. This meant that minorities, who were largely excluded from the white Democratic Party, had no real voice in the political process.

Why Was the White Primary So Effective at Preventing Minorities