Answer:
Expert witness testimony.
Explanation:
Constituency-building strategy tool are the things that we can use to improve our political influence.
Expert witness tend to be called to strengthen our defense when we're involved in a legal case. (for example, when you want to proof a murder, you might invite a famous forensic scientist to aid you with your case). It has no correlation to increasing political influence.
Garvey emphasized black pride he founded the Universal Negro Improvement Association.
Garvey's ideas were rejected when he pushed the idea that Black and White are irreconcilable.
