It’s not the only reason for Trump’s victory, sure. But isn’t one of the takeaways from the last three presidential elections the immense political power of celebrity and cool? The Obama coalition that Clinton did not mobilize may have depended on having the first black major-party presidential nominee at its head. But it also depended on getting low-propensity, low-information voters to show up to take part in a cultural phenomenon. Clinton couldn’t do that, even with Katy Perry’s help.