Ezra Klein offers us this puzzling graph:
Americans worship winners and they don't really care about unfair process. This is the nation that reveres the quote “winning isn't everything, it's the only thing.”
Similarly, the party in power is expected to do what's necessary to pass its agenda. If it can't, it is held responsible for the failure, not those who stopped them from doing it.
And there is another dimension to this which especially applies to the Obama administration. Since he ran explicitly on the promise to end the bickering, change Washington and create a post-partisan consensus, people see the failure of those things to materialize as a measure of his failure to deliver on his promise.
We can expect more Republican obstructionism to come.