we were the world/we know we knew/that we could change/could stop the drought/and we saw the end in sight/it would change could change.
you and I were not enough/alone we were the world/we sought the keeper sought the gate/and then the river flowed.
This part is about people who are new in the adult world. They could be fresh out of college or high school, or whatever. Please note that this is the age group that Hitler targeted for Nazi propaganda. These theoretical people are idealistic and are ready to change the world for the better, or "stopping the drought" (of oppression of their people, which, for example, was a result of the Treaty of Versailles for Germany). To do so, they turn to a particular political party (such as the Nazis) that promises them achievement of their goals. However, often this achievement is very detrimental to society because it is overdone (i.e. revenge for the Treaty instead of reparation), for example, releasing a river upon a desert, thus destroying the habitats there.
the pathos of our destiny/seemingly random and complex/
became a pattern that lulled us/lulled our senses to sleep.
OK, so now these people have joined the party, which is under the power of (in our theoretical situation), Hitler, who was undoubtedly an unstable person. Hitler, or whoever it is, in the name of doing something as in getting revenge for the Treaty of Versailles, does a lot of other things that are violent and probably have nothing to do with this goal, such as the anti-Semitic sentiment that led to the persecution of the Jews and other minorities. However, those involved in the party become desensitized to such things because they are working to their common, idealistic goal.
and when we all had gotten drunk/gotten drunk and gotten fucked/ finally you said enough/ turned away from all we saw/and the raging river was no more.
This part is just closure, really. Getting drunk refers to the previous stanza in which they become intoxicated upon whatever political party (HINT: Nazis!) they have joined and therefore have a skewed perception of reality. Getting fucked does not actually refer to a sexual act: it just means that the party exploited their resources while they were "inebriated." Basically, one of the original people takes a step back and realizes the detriments of the "raging river," but it's really too late and isn't important.
So in summary, it's all about Nazis. Or Republicans. Nyah.