> called "liberal" dominantly for some decades, some adopted the moniker "progressive" when it was perceived that the right had created bad associations with "liberal" a few decades ago

This is not supported by history in any way. This wikipedia article [1] is a good place to start. There are other explanations on Quora [2] [3]. These are not primary sources, but they have the relevant references.

[1] https://en.wikipedia.org/wiki/Liberalism_in_the_United_State...

[2] https://www.quora.com/When-did-the-term-liberalism-come-to-d...

[3] https://www.quora.com/How-did-it-come-to-be-that-in-the-USA-...