Does the game ever comment on how Booker somehow managed to become what we are to believe is something akin to the president of the united states?

The game states, almost as an afterthought, that Columbia built to show off American prowess, but was Comstock in charge when it was on the ground? Did he have some role before he was "The Prophet"? Was he elected into Office? Did he have duties aside from prophesy? How did he become the religous leaders and the "President", I guess, at the same time?

I recall some talk about the Senate and such, so maybe Mr. Comstock was a Senator or a Congressman and was the leader of the Columbia project. However I find it very hard to believe that Comstock was President. Columbia ended up severing themselves from USA so I don't think a President would do that.

That said, I don't think there's anywhere in the game that explicit states the "role" of Comstock before being the Leader of Columbia.

Yeah, he's not the president, he just later decided to part ways with the US. He was obviously an influential person, managing to get funding for his vision of Columbia, but the game doesn't really address how that happened.

My understanding is this: He became "the prophet" by using the machines the Luteces built to look into the future and other universes. That way his predictions and prophecies were accurate and he accumulated followers that gave him enough power to rule Columbia. The Luteces were also responsible for making Columbia a floating ciy. In the Voxophones by Rosalind Lutece is a bit of explanation on that matter, but not much. Maybe Comstock and the Luteces allied and created Columbia? Or they took over the city of Columbia and sent it into the sky?

I like that the game does not answer all the questions :-) .

yo waddap girl lutece, iz ya homie Zachary Cbaby. I wanna make sum crazy ass city cause I hate this earth n stuff ya dig

sure cbaby lemme just get some of dat crazy flying juices and a grant from the guvrnment.

And the rest as you know it, is history.

Comstock saw a "prophecy" of Columbia shortly after the baptism, either on his own or through the help of the angel "Columbia" who might just be an alt-reality Elizabeth. He sought out Lutece and, with her research, presented his plans for the floating city to the US government. The US granted them funding and construction began, with Comstock providing the vision and Lutece providing the know-how. The city was launched at the World's Fair: Columbian Exhibition in Chicago in 1893. Over the next eight years Comstock was able to build up a cult of personality around himself as the man in charge of Columbia until, in 1901, he commanded the city to attack Peking in response to the Boxer Rebellion. The government disavowed his actions and ordered the city recalled but, at that point, his grip on the populous was too strong and Columbia instead seceded from the US.