Anyway, this is all boring stuff from here on (oh, wait, what changed?)
Of course, I've got all sorts of things going through my head, but I'm tired, so instead of doing anything useful like writing it (even though I've got at least a dozen key scenes all but written in my head, including the first few), I spent most of the night at work here re-writing the U.S. constitution to make it more appropriate for taking over, er, absorbing the world. Which isn't quite as hard as it sounds with only about 300 million survivors world-wide and a few other factors in the mix. Spent too much time with Wikipedia and a spreadsheet working out that I'll end up with 271 states -- including 53 US states, not counting Puerto Rico which isn't really special anymore (and ended up getting lumped with a bunch of other islands), splitting California and Texas, and creating Columbia out of DC, a chunk of Maryland, and a little bit of Virginia (now that the federal seat's been moved to Denver for practical reasons, and, well, to make things more politic).
Anyway, cleaned up the constitution (modernized the spellings, merged the amendments into the main body, removed or updated some out of date provisions, etc, futzed with the capitalization). Made it more suitable for colonization writ large (removed anything related to militias and the right to bear arms, changed the structure of the Senate and House slightly to make it less representational in order to preserve American political power as much as possible without making it too extreme -- the House is a lost cause fairly quickly, though -- a strengthened but limited filibuster, plus some things to reduce the power of the federal government, like an explicit ban on unfunded mandates (I'm looking for more on that, it doesn't seem sufficient, since I want to limit the legislative power of the federal government as much as possible without compromising its ability to raise cash for the war machine. More autonomous states are easier to absorb). Also, made English the official language for federal business and the military. Put in some stuff for the hell of it (term limits, a maximum term for patents and copyrights). And stuff actually important to the plot -- an explicit ban on abortions, a "marriage amendment," and, of course, I replaced the language for Indians with Aliens. :)
Hmmm... Might want to add explicit privacy rights (on second thought, maybe not) and... Damn, I forgot the other thing. Might want to see if there isn't something that needs to be addressed with a space-based military-industrial push going on. Maybe something about residency rights. Especially with people getting shipped all over the place with an independent federal corps of engineers which (for obvious reasons) ended up being by far the biggest arm of the government.
And all that's probably going to go end up being referred to in passing in a single paragraph. Maybe. And doesn't have a whole lot to do with the story, anyway, it's just background. It's when they're on the rebound, anyway, before things really go to hell.