The problem with our current government and the US political system in general is that it is geared entirely around winning elections. Nobody actually wants to make the country a better place or do what's best for the largest portion of people; they want to win their next election. So you get a guy in office (e.g. Obama), takes a year to get settled in, might try to do some things the 2nd year, then it's time to work on getting re-elected again.
Obama in particular set himself up for a rough time I think by running such an incredible campaign. The 2008 election was such an overwhelming victory not just for him but for the Democratic party as a whole that I think it really opened some eyes in the GOP, who could have gone one of two ways afterwards:
(1) Realize they're not what the American people want in their leaders at the moment and shift left, work with the left, or try a different approach altogether (not what happened)
(2) Galvanize their party together and redouble their efforts, re-energize their base, i.e. stick it to the Democrats (what happened)
So now we're at a point where the two parties are completely gridlocked and won't work together at all, because if say you're a Republican and you support something a Democrat does, you'll get massacred by your in-party rivals in the next primary for doing so (and vice-versa for the Dems). Both parties just oppose and renounce any and everything the other party does, simply because it's "the other party", and it's all geared around greed, power, and winning, and not at all around what's actually important.