The Congress' approval rate dropped to a historical low of 10% this year and this is mainly blamed of the extreme partisanship in Congress.
The Congress was not always that polarized, this is a recent trend when looking at the history of partisanship in Congress over the last 220 years.
The following infographic, provided by xkcd, illustrates the idea of how the more extreme part of each side of the aisle grew over the years leading to less bipartisan initiatives.
The legend of the timeline: 
