The fight for control of the party is an old one going all the way back to the days of Rockefeller, Carnegie, and JP Morgan before the McKinley/Rockefeller election trying to rule the nation. That is actually where the term Rockefeller Republican originated. He was a Progressive as in meaning a Liberal. Rockefeller for all practical purposes after Lincoln was the father of expanded federal government and federal powers.
Clarification: A Rockefeller Republican back in the days of John David Rockefeller, JP Morgan, Carnegie, was supporting William McKinley a fiscal Conservative. They manipulated that election by having Teddy Roosevelt as VP and were betting Teddy would never be POTUS. They lost. Nelson later on was the Liberal Republican and where the term Rockefeller Republican was to mean Liberal. After the bust up of Standard Oil it seems Carnegie and Rockefeller got into a charity competition and thus the generations to follow leaned liberal including Nelson Rockefeller. Here is some interesting info on the Rockefeller causes. https://en.wikipedia.org/wiki/Rockefeller_family