Again, that depends on how the next 4 years go.
Scenario 1: Somehow everything goes right for Mr. Obama, he has a bit of trouble with Republicans in Congress for the first two years of his second term, but in mid-term election somehow they're all voted out and the US recovers fully. Somehow at the last minute--when all hope seems lost--Europe finds a way to solve its financial crisis, and China decides to continue its economic growth. Netenyaouh doesn't go batshit crazy on Iran, the Middle East remains an ambiguous quagmire, but we deal with them less and less as cleaner, greener technologies are depended upon as Obama focuses on infrastructure and resurrects the CCC and WPA. Hillary might win an election in 2016 as a "keeper of the Obama tradition", but we all know the history of political parties who win three elections in a row: she wouldn't get re-elected in 2020. It would invoke the Jackson-Van Burean/Roosevelt-Taft/Reagan-Bush law of successors from previous successful presidencies. However, most likely after having 8 years of a Democrat in power, the public would most likely vote a Republican in just to bring "balance" back into the equation. Especially considering the Republican Xers Hillary would be up against who are much more charismatic than she is. American High round II starts.
Scenario 2: Obama is re-elected, but the Republicans in the Congress want blood for losing the election and effectively continue to kick the can down the road and block any and all actions of government, hoping for a repeat of 2010 in 2014--and actively working for it. The European financial crisis continues to get worse (as it looks currently), which puts a dent on the current "recovery". China releases its five-year economic plan which is to downgrade its rate of growth for the next five years (hint--I've heard word that this one is actually going to happen), which puts another dent in our current "recovery". Israel suddenly and shockingly attacks Iran without warning, forcing Obama to commit more troops to another foreign war, just after getting us out of Afghanistan. Only this war is a bit worse as a rogue Israel makes every other Middle Eastern country united in wanting its defeat--effectively making the moderate Muslims disappear and bringing the extremists to the front in all the Arab Spring countries. And here we are, essentially fighting off the entire Middle East. Europe is too absorbed in its own financial problems to do anything. Russia and China meanwhile play both sides, trying to profit from the situation as best they can. Essentially this leaves Obama in a state worse than Hoover and ensures a surefire win for the Republicans in 2016--demographic change or no demographic change. And I can bet you, by 2016 that that Republican won't be some moderate wannabe conservative rich boy from Massachusetts like Romney, that it'll be a dyed in the wool full out conservative Xer who'll have much more charisma and bankroll off of the dislike for Obama.
Scenario 2a. The Republicans fail to have a repeat of 2010 in 2014 (somehow?) and we devolve into a Civil War of sorts. It's bloody at first as the battles are waged in every state, eventually though the Republicans coalesce in the South reforming the CSA. And the Democrats coalesce in the North & Mid-West, keeping the USA or a variation thereof. The West says "screw you guys" and becomes PSA & RMSA. And the former USA stays fragmented as no one would want to force us all back together again this time. Too often I've heard sentiments of "we should've let the south secede when we had the chance" on this board and in real life.
Scenario 3 - Romney is elected and everything goes like in Scenario 1. Thus ensuring his re-election in 2016. Somehow Romney is able to contain his desires to go to war with Iran, as is Israel--thus keeping us from getting entangled in an even more costly war. Because I just about guarantee that we're going to war with Iran if Romney wins--call it a very confident gut feeling. Another difference being he has an easier time with Congress (until the mid-term elections) and is able to depend less on foreign oil by opening Alaska up for drilling. Green energy is not focused on at all. Gilded Age III starts.
Scenario 4 - Romney is elected and everything goes like in Scenario 2... in fact it would probably be worse as Romney would not only encourage Israel to strike Iran, he might even get the silly idea in his head to make the first strike himself, which would potentially start WWIII if Russia and China decide to get involved and pledge to curb and contain "US aggression" throughout the world. And the world is more likely to go along with them as Romney isolates potential allies with smug gaffes (like the one he let slip in England during the London Olympics) as they're sick and tired of what looks to be an elitist and overly aggressive US that has been playing a game of invasion for the past decade and a half and has turned from the "global police dog" to the "global bully". That ensures a bloody and destructive global war that comes to US shores. That is when you can start bringing up Candyland dreams of Hillary winning by a landslide in 2016, if there's anything left of the country by that point.
Those are the five scenarios most likely to occur. Of the five, #1 is least likely to occur given how the rest of the world is looking to evolve and the Republican Congress is less likely to be "willing to work" with Obama--at least with those retribution bound Tea Party and Boomer Republicans in office. #2 or #4 seem the most likely to occur at this point. #3 is simply wishful thinking. #2a. is a worse case scenario that's just a tad more likely to occur than #1.
~Chas'88