The New York Times has some graphics that should kill the “both sides” narrative, but they won’t.
[The] findings are based on data from the Manifesto Project, which reviews and categorizes each line in party manifestos, the documents that lay out a group’s goals and policy ideas. We used the topics that the platforms emphasize, like market regulation and multiculturalism, to put them on a common scale.
The resulting scores capture how the groups represent themselves, not necessarily their actual policies. They are one way to answer a difficult question: If we could put every political party on the same continuum from left to right, where would the American parties fall?
The Democratic Party is leftish, the Republican Party, extreme.
An explanation is easy to see in two parts. Part the first: Tea Party primarying forces moderate candidates to the right or out of the race. Part the second: Reasonable people leave the Republican Party.
It’s also an argument against courting the flyover diner crowd, but none of that will change the media.