There is an element of the blue base which believes that civility amounts to unilateral disarmament in the face of Trump’s provocations. Leaving aside that uncivil behavior inevitably provokes an angry right-wing backlash, the fact of the matter is that Trumpism is the enemy to be vanquished in November–not just Trump himself. Replacing right-wing Trumpism with a left-wing version of the same thing would not be much of an accomplishment.
And so, being civil is not unilateral disarmament, and it is not simply the right thing to do; it is the very essence of the struggle for liberal democratic values which should be at the heart of the campaign.