I think the major parties and other interested organizations will always have forecasts like these available internally, and will leak them (or lies about them) when it's to their advantage. Having a high-quality forecast directly available to the public can't hurt more than that.
> I sometimes think they may be harmful, decreasing voter turnout by convincing people (correctly or incorrectly) that the result is preordained.
This is an old tactic that is used to the hilt by both sides whenever it serves them, and media outlets already make forecasts, often without 538's scrupulous emphasis on how often they're wrong. I don't think 538 makes this worse.
> I sometimes think they may be harmful, decreasing voter turnout by convincing people (correctly or incorrectly) that the result is preordained.
This is an old tactic that is used to the hilt by both sides whenever it serves them, and media outlets already make forecasts, often without 538's scrupulous emphasis on how often they're wrong. I don't think 538 makes this worse.