Obama doesn't get killed. He goes silent like Bush after we get a Romney/Biden presidency in 2012 thanks to rogue Electoral College electors seeking to punish the parties. It's a massive clusterfuck for another two years (Romney trying to run the country through executive order and Biden touring the world essentially asking for foreign assistance in a coup) until Romney DOES get killed (by an evangelic nutjob, after trying to, I shit you not, legalize polygamy) and Biden 'resigns' (vanishes), leaving us with President fucking Pelosi. We come closer to a civil war than we ever have (except, you know, the actual Civil War), but in the end the American people really are too fucking lazy. Federalism changes massively, 'Dumbfuckistan' becomes a real thing, given de-facto recognition as a co-federal government (rampant with corruption and run by a conglomerate of evangelical churches). Analysts warn strongly that this situation WILL lead to a Civil War within a generation, so we're all just witing to see what happens. No, we never did get rid of the Electoral College system. China is a non-issue in all of this, neutralized beginning around 2015 by their own catastrophic economic collapse. But Russia is resurgent in the arctic sea, and basically whooping our asses.