Liberals argue that, “we have to be better than the enemy”.
The enemy then argues that, “we have to help liberals get elected”.
Those who wish to discourage evil should endeavor to treat others *slightly* better than those others treat them. Letting others know that both good and bad actions will be reciprocated will encourage those others to engage in good actions, so they can receive a favorable response and avoid an unfavorable one. Conversely, letting others know that no action by them will net a negative response will encourage them to engage in bad actions, since they will lose nothing by doing so.