Does anyone else feel this all started with Sarah Palin?

[Bernardo de La Paz]

48. NO. Started with Birchers & fluoridation & Nixon & tanks & Gingrich & Fox & W & Palin. In other

In other words, it is the culmination of a long effort by Republicons.

John Birch Society members had that same crazed conspiracy anti-gubmnt gleam founded on some racism and a lot of nonsense. They overlapped with the fear-mongering anti-fluoridation nuts.

Nixon brought in the Southern Strategy because he agreed with Johnson's assessment of the costs of his Civil Rights legislation.

Johnson reportedly told associates of his concern that signing the bill had lost the white South as voters for the Democratic Party for the foreseeable future. -- Wikipedia

https://cehdvision2020.umn.edu/blog/conservative-think-tanks/
How Conservative Think Tanks Helped Create the Age of Trump
Fri Aug 12, 2016 by Jason Stahl, Ph.D.

The Heritage Foundation was founded in 1973 by Paul Weyrich, Edwin Feulner, and Joseph Coors.[6] Growing out of the new business activist movement inspired by the Powell Memorandum,[7][8] discontent with Richard Nixon's embrace of the "liberal consensus" and the nonpolemical, cautious nature of existing think tanks,[9] Weyrich and Feulner sought to create an organization that would supply policymakers with concise, timely position papers. With $200,000 from Coors, the Analysis and Research Association was created in 1970. New supporters and board members joined, including petroleum executive Edward Noble and Richard Mellon Scaife. Eventually, the organization split into a public interest law center and a separate public policy foundation, the latter of which was incorporated as The Heritage Foundation on February 16, 1973. Weyrich was its first president. -- Wikipedia

Think tanks developed the idea of framing the language, a way to dumb down political debate. Gingrich embraced this. Republicons started talking about "death taxes" instead of estate taxes and "pro-life" instead of anti-abortion rights.

George Lakoff: https://www.berkeley.edu/news/media/releases/2003/10/27_lakoff.shtml

Karl Rove very explicitly preferred to win by a more secured slim majority than going for a possible larger majority. This greatly increased polarization in the country which reduces debates to shouts of "commie" and "fascist".

Fox News pushed a faux viewpoint and the rest of the mass media generally obliged because they like horse races for increased viewership leading to increased advertising sales leading to increased profits.

Palin was the "dumb as rocks" flint arrowhead, not the wood behind the arrowhead. A wedge and a "Caribou Barbie" to appeal emotionally.

So, no, Palin & Schmidt were not the cause or the first.