I dunno. There are two kinds of such books - those published before the ascension to power and those published afterwards (the Little Red Book is one example of the latter.) Only books of the first kind might have contributed to the author's rise to power, but it's hard to tell how much, and at least intuitively it doesn't seem like any of the leaders you mentioned rose to power mainly due to their writing ability.

I think it's interesting to read the writings of an influential person, and sometimes it is mandatory to read them even if it's not that interesting, but I doubt that these people mainly become influential through their writing (at least the effect seems much smaller than the reverse - books becoming widely read because of the author's influence on world events.) It certainly works in both directions, I just think one is much stronger than the other.

The pen and the sword... well, persuasion is mightier than an individual's brute force because you can mobilize the force of others through persuasion. But is "pen" the right metaphor for persuasion in a world where both dictators and democratically elected leaders rely on the support of huge groups of people, many of whom rarely read, have poor reading comprehension (don't we all? especially when reading what we disagree with?), and are most easily swayed by simple ideas boiling down to "the source of your troubles whom you should rob to improve your life is X"? If the world is run a by a literate few born into a powerful minority, then perhaps a pen might be more powerful.

As to religious texts... I think they're kinda different in that say Lenin's writing could rival the popularity of religious texts for a while, at a time when printing was very cheap, but it no longer can. Contrast that to religious texts which remained popular for hundreds and thousands of years at a time when reproducing texts was very expensive. And there was never a lack of either tyrants or statesmen with popular support during those years, moreover, quite a few of those tyrants were worshiped as gods, and both tyrants and elected politicians wrote texts. None of these texts are remotely as widely read as religious texts.

So whatever the cause, the handful of popular prophets are vastly more popular than any of history's politicians, and are way better at maintaining their influence from their graves.

You could add Kennedy's "Profiles in Courage" and a few others I think (Huey Long and "Every Man a King" for instance).

In the case of both Kennedy and Obama the book was used in combination with great oratory skill to introduce the candidate to the people: You hear an amazing speech by the candidate and want to learn more. You find they have written a book and decide to read it. The book gives you a feeling of intimacy with the candidate which turns you into a supporter.

There's a lot of people who become filthy rich, and get to publish a book.

Kim Kardashian could string a few sentences together, and it would be a best seller.

I am throughly shocked at what people read. I just don't get it.

(One day I will read Obama's first book. Why--because I believe he will go down in history as one of our better presidents.)

a) I didn't know that Trump had written something called "Crippled America." b) Explaining Obama's rise by means of his books is a stretch; how many people actually bought and read them? c) It seems to me that the popularity of the Little Red Book came from Mao's power, and not vice-versa.

This is true. It seems that if you're looking to leverage your literary talents for political/commercial ends (Cicero, Pierre Trudeau, Paul Graham?, Locke, Franklin, Václav Havel, Michael Ignatieff, etc.) you probably need access to wealth to fund your writing career in the first place.

The lone exception being that excitable German with the Charlie Chaplin moustache...

I think his mother made off with a lot of the cash that should have been his.