One of the biggest things that the president, and really anyone in a high or noteworthy level of office can wield, is the bully pulpit. Their ability to speak to people and basically be guaranteed that people will listen to what they’re saying, even if they get clip-chimped by fox news or the nyt or cnn or whatever. “Inspiration” is something that can drive people to the polls, too. Having a candidate that the majority of the population trusts and can believe in, i.e. is inspiring, is better than having a candidate that isn’t those things, broadly. Well, if you agree with their goals, anyways.