NPR breathlessly reports on political trends with a fancy looking chart reproduced below in an online report entitled "Political Scientist: Republicans Most Conservative They've Been In 100 Years". 

"Keith Poole of the University of Georgia, with his collaborator Howard Rosenthal of New York University, has spent decades charting the ideological shifts and polarization of the political parties in Congress from the 18th century until now to get the view of how the political landscape has changed from 30,000 feet up. What they have found is that the Republican Party is the most conservative it has been a century."

The report goes on to quote Poole who has been working on this "for decades" and "who's viewed by other political scientists as the go-to expert on this issue".

"This is an entirely objective statistical procedure. The graphs just reflect what comes out of the computer. Howard Rosenthal and I, we've been working on something called Nominate. This does all the Congresses simultaneously, which allows you to study change over time."

But wait a minute?  How can you define what is "conservative" and "liberal" in the late 19^th century from a 21^st century perspective?  I am not an accredited historian, but the 1880s marked the end of the post-Civil War Reconstruction Era. During Reconstruction, blacks were elected to congress as Republicans.  The end of Reconstruction was characterized by the rise of the Democratic Party to one-party rule in the South which lasted for the most part until the 1980s.  The Democratic party used their power to impose Jim Crow laws and turn a blind eye to racial terrorism perpetrated by the Ku Kux Klan. 

"Jim Crow was the name of the racial caste system which operated primarily, but not exclusively in [Democratic Controlled] southern and border states, between 1877 and the mid-1960s. Jim Crow was more than a series of rigid anti-Black laws. It was a way of life. Under Jim Crow, African Americans were relegated to the status of second class citizens. Jim Crow represented the legitimization of anti-Black racism."

In what universe would this era of Democratic Party rule be consider more "liberal" on the scale above than the Democrats of 1945 or 1975?  But because it was "computer generated" NPR is credulous (gullible?).  As they say in computer science, "garbage in = garbage out".  I find it astonishing nonetheless that "political scientists" accept -- and that universities actually pay these "professors" for -- such garbage.