see url:
https://www.quora.com/Is-it-true-that-Democrats-used-to-be-the-conservative-party-and-Republicans-used-to-be-the-progressive-party-Im-sure-the-whole-truth-is-more-complex-than-two-parties-switching-their-main-ideologies-but-what-is-the-truth
There you are...there is always an answer on the world wide web...:-)
Food for thought,
ATB
Dougie.