Negative ads dominate campaign communication, but scholars continue to disagree over the effects of negativity on voter turnout. While some studies show that negativity leads to a lower likelihood of turnout, others find precisely the opposite. In this article, I leverage the role of timing to unify findings that were heretofore perceived as largely conflicting. I use the same data to show that at a certain time exposure to negativity can be mobilizing, but at other points in time exposure can be demobilizing. A combination of observational data and experimental results highlight these crucial conditions.