You have to look at authentic Rastafarianism from the historical standpoint in which it arose.
The idea that Ras Tafari (Emporer Haile Selassie I) might be the second coming is severely debunked by the fact that the dude is dead and none of the prophecies have come true. Of course, this hasn't kept the followers of Yeshua Ben Yoseph of Nazareth from holding a torch that he was the meshiach (messiah) predicted by the prophets either.
To understand why a downtrodden people who had the Bible shoved down their throats might imagine the former emperor of Ethiopia to be the 2nd coming, you have to look at a few facts:
1) The Bible says that the messiah would be from the house of King David. Ras Tafari was one of the few people on Earth who could prove a direct blood relation to King David. David's son Solomon married the Queen of Sheba (Ethiopia) and had
Menelik as their son. Menelik became the first in an unbroken (supposedly) chain of emperors that lead to Selassie. While it seems that this was not a direct father to son chain as many believed, it is likely that Selassie did in fact carry the blood of Solomon. (Though, by now, considering how many kids both David & Solomon had, this could be said of a very large number of people.)
2) Ethiopia was the only empire (or even kingdom) in Africa that was unconquered and uncolonized by the Europeans. A source of pride for the people of the African diaspora.
3) Selassie beat Mussolini's modern army (tanks and machine guns) with an army composed of horsemen with sabers and a small number of firearms. (The Italians had already taken over Djibouti, and were well on their way to colonizing Somalia and the entire Horn of Africa.) Mussolini even had help from Hitler's Afrika Korps and still got his ass handed to him by Selassie. This was perceived by the people of the time as a miracle, and further proof of Selassie's divinity. (Actually, the Bible says nothing about the messiah being divine, but that is another story.)
4) The Bible describes the meshiach as being the "Lion of the House of Judah." Judah, of course was one of Jacob/ Israel's sons and the father of the tribe bearing his name from which King David arose centuries later. Perhaps not-coincidentally, the royal seal of the Ethiopian empire was this Lion of Judah symbol. A conquering lion motif superimposed on a Star of David. This flag and symbol was always shown in concert with images of Haile Selassie... and thus pushed this idea further into the minds of people who wanted to believe that the savior had come.
5) The Bible says the messiah would be a "king of kings & a lord of lords"... pretty much the definition of an emperor.
Naturally, Selassie himself denied being the messiah. He made it clear enough that Rastafarianism didn't take root in Ethiopia where people practiced Ethiopian Orthodox Christianity for the most part (with pockets of authentic Falasha Jews). Ethiopian Christianity is much closer to Judaism than anything the west practices... even moreso than Seventh Day Adventists. Only messianic Jews are closer Christians.
However, in far away little Jamaica, they didn't get the message. Selassie's official state visit to the island didn't help matters as many devout rastas claimed to have transcendental experiences from seeing him.
There is more to it than this, but I don't want to pen an essay on Rastafarianism here. There are many amazing and powerful things about Rastafarianism and rastas in general, Ital food, Nyabhingi, Reggae etc. The fact that these things have little to do with Selassie and are more examples of Jamaican roots culture notwithstanding, there
is much to be learned from this influential cultural movement. It seems rather strange to hold onto ideas of Selassie's divinity when he is long dead and gone, but this is not completely unprecedented as I said before. In fact, there are
many groups who maintain that their lost leaders were the messiah, and will get out of their coffins or whatever when the time is ripe. The Hasidic group Chabad has a branch that still thinks the Lubovitcher Rebbe is the messiah, and he has been dead for almost 20 years. North Koreans venerate both Kim Jong Il and his predecessor Kim Il-sung as being divine saviors... and their official website proclaims that neither of them will ever leave their people.
Amazing what people will believe if inspired.
"Curiouser and curiouser..." ~ Alice
"Do not believe in anything simply because you have heard it. Do not believe in anything simply because it is spoken and rumored by many. Do not believe in anything simply because it is found written in your religious books. Do not believe in anything merely on the authority of your teachers and elders. Do not believe in traditions because they have been handed down for many generations. But after observation and analysis, when you find that anything agrees with reason and is conducive to the good and benefit of one and all, then accept it and live up to it." ~ Buddha