Political Gridlock: It's The American Way!
No matter who gets elected president close to half of the people will have voted for (the other person). That's a lot of unhappy people!
The first 4 years are used by the "opposition party" whichever side that is to ensure the sitting president is not re-elected.
The best way to achieve that is to make sure very little of their agenda is passed into law. Both parties expect their representatives to vote as one block. Anyone who doesn't risks losing support of party leaders. Having a vast majority of seats helps.
The way political parties view it is if things go very well for the nation the people will automatically re-elect the current sitting president.
There is no real incentive for bi-partisanship. Party loyalty trumps the people's needs or wants. In fact most voters don't want to see their representative socializing with "the enemy"!
Chris Christie caught hell for thanking Obama for the government's fast response to Hurricane Sandy. John Boehner got flack for once playing golf with Obama.
It's as though politics has become a "sport". Each party has it's fans.
No self respecting Laker fan would cheer for the Celtics or vice versa. Bipartisanship is viewed as treason by some folks!
If the president is not someone you voted for then just about everything he/she does is going to be "wrong" in your eyes.
Lastly requiring voting percentages in congress to pass a bill instead of a simple majority vote contributes to gridlock. One party may have 59 seats in the Senate and the other party has 41. You need 60 to pass a bill. Unless some people from "the other side" whichever side that is votes against their party's wishes not much gets done.
At times both parties have speculated on making voting rule changes but then they consider what might happen if they ever found themselves being the minority party. In the end they support the higher voter threshold to pass bills and override presidential vetoes.
Truthfully the president is little more than a figurehead in most instances. Congress drafts bills and passes legislation. A president may have an agenda but his or her success is based upon whether congress enacts laws they attempt to push through. Even if the president fails to keep his/her promises voters reward them for making the attempt to get their agenda through. If one is favor of raising the minimum wage or abolishing abortion but congress votes against it most voters won't blame the president. They'll blame their opposition.