Jeremy Young explains what he explored in his book on the charisma of politicians between the Civil War and World War II:
One of the central questions I had to answer in researching my book on turn-of-the-century charisma was how to determine whether a given leader was actually charismatic. Charisma is an enigmatic quality, both ineffable and deeply subjective; who was I to say that Theodore Roosevelt was more or less charismatic than, say, Woodrow Wilson? Ultimately, I realized that I was asking the wrong question; charisma was not a characteristic of leaders, but a relationship between them and their followers. By observing how Americans described their leaders, then, I could let followers do the work of identifying charisma.
H. L. Mencken had another theory. It was whether or not a politician had “it.” Mencken thought Al Smith did.
There is something about Al’s aspect that the plain people like, not kowing why, and they seem to like it almost as well where cops are curiosities as where cows are curiosities. I have watched them at a dozen country railway stations, crowding up to the observation platform. Maybe the stop is for but two or three minutes; sometimes there is no more than a slowing down. They crane their necks expectantly, waiting for they know not what. Suddenly Al is on view, waving the brown derby, reaching out to shake hands, hauling in the bouquets brought for Mrs. Smith and joshing the local worthies. They regard him quizzically for a moment, and even with a certain hostility, but then, of a sudden, he has landed them, and as the train rolls on they are howling. . . .
The plain fact is that Al’s points are mainly infra-red and ultra-violet. It is impossible to chart or label them. He simply has the thing that the movie folk call IT — and the movie folks discovered long ago that it could not be described with any precision. There are grand and gaudy beauties who lack it altogether, and there are shabby little girls who radiate it at a pressure of a million volts. Al has it as no American politician has had it since Roosevelt. Has more of it, indeed, than Roosevelt, for the popularity of Roosevelt was largely logical: the plain people admired him because he had waded in blood and saved American womanhood from the Spanish Hun. But they know very little about Al, and what little they know, at least in these back reaches of the land, is mainly unfavorable. I don’t think it would be exact to say that they admire him, even after they have seen him. But it is as plain as day that they delight in him. He somehow thrills them and makes them happy. When he casts his magic over them it penetrates to their gizzards. (“Smith Has ‘It'” – 1928)
I suspect that Hillary didn’t have it but Trump did.
Postscript: Machen voted for Al.