Sorry, but you are looking at early 20th century history thru a lens created in the last few decades.
It's only during this period that the Democratic vs. GOP opposition has correlated (more or less) with the liberal/progressive vs. conservative split. During previous decades both parties had conservative and progressive wings.
In fact, our party politics have gotten a lot more rational since about 1970. Before that they made little sense at all.
At that time there were still people around, active Conservatives, who'd known TR, FDR and the Taft's personally.
BTW, back then we used meeting halls and the mails to communicate ~ worked just as well.
The dichotomy you're talking about as having not occurred until recent times IS WRONG ~