An attempt at a steelman argument is that it has the potential to influence the outcome by shifting voter attitudes. If we consider the 2016 election, since mos

An attempt at a steelman argument is that it has the potential to influence the outcome by shifting voter attitudes. If we consider the 2016 election, since most predictions were leaning so heavily towards Hillary Clinton that might've caused her supporters to be less likely to go out and vote, thinking that she's already likely to win so there's no need for them to participate. If the messaging had been that the election is going to be extremely close and every single vote matters then you might've gotten improved voter participation. At least this is one variation of argument which I've encountered, but I'm not sure if there's strong empirical research to back up the claim. After the lesson of 2016, messaging about election participation for 2020 was much more active which lead to the highest voter turnout of the century. Edit: Upon further reflection, I'm actually not fully convinced of this line of thinking. Or at least I think it's not a fully accurate representation. We can also consider the other perspective in 2016, if Donald Trump supporters had thought the election was hopeless because of polling, they probably wouldn't have bothered to go vote. Although my understanding is that Republicans are already inherently less trusting of these kinds of systems, which might provide a plausible explanation for why they weren't as negatively affected.