Final answer:
The tactic called packing concentrates like-minded voters into one district to diminish their voting power elsewhere, a strategy used in gerrymandering to minimize their overall influence.
Step-by-step explanation:
The tactic that involves concentrating like-minded voters in one district to reduce their voting power in other districts is known as packing. By drawing district lines to ensure that a particular group is dominant in just a few districts, their overall influence is minimized across the region. This strategy, often used in gerrymandering, can result in minority-majority districts, which, while guaranteeing political representation for minorities, might also dilute their overall power.