It's been said that American politicians have grown more entrenched along party lines and less willing to compromise.
Here's a GIF that illustrates just how correct those assumptions are:
A person on Reddit with the handle "grepawk," who apparently created the graphs, explained on the message board that the illustrations show how often senators vote the same way.
"They were made using Gephi and data from govtrack.us. An edge between 2 senators indicates that they have voted together on at least 100 occasions; I filtered out edges with lesser weight for the sake of clarity."
Here's a graph from 1989.
During the 101st Congress of 1989, senators could agree on a few things. They compromised. Note the purple (red Republicans mixing with blue Democrats) in the center of graph and the relatively short distance between senators.
Now, hop in your DeLoreon, and set the time circuits for 2013. These days, according to the data, the chamber has split into two distinct camps. (Still no flying cars, though.)
It's worth noting who the outliers are in each party. Among those furthest to the left in 2013 are Barbara Boxer, D-Calif., Elizabeth Warren, D-Mass., and Patty Murray, D-Wash. Those on the far right include Ted Cruz, R-Texas, Rand Paul, R-Ky., and Jim Inhofe, R-Okla. The centrists: Lisa Murkowski, R-Alaska, Susan Collins, R-Maine, and Joe Manchin, D-W.Va.
Back in 2004, then Illinois state Senator Barack Obama riled up the crowd at the Democratic National Convention when he declared, "There is not a liberal America and a conservative America. There is the United States of America."
Nine years later, the polarization within the Senate says otherwise.