Do vice-presidential candidates affect presidential races?

In The Atlantic, Lora Kelley digs into the complicated reality of what role nominees for vice president have in determining election outcomes. This, plus polling about J.D. Vance, gives me optimism about Kamala Harris’s campaign, and I have some thoughts on Senator Mark Kelly’s credibility on a unique set of important issues.

‘Why protest when they could proselytize?’

But why protest when they could proselytize? For the reasons acknowledged by Krugman, Brooks, and Page, Trump’s attracting marginalized Americans. Some are racist thugs, but others are victims of circumstance and the very Americans for whom, though apparently not to whom, Bernie Sanders, for one, says he speaks. Why do Trump’s opponents antagonize these people when they could be trying to win them over?