I don’t claim to be an authority on American politics between 1880 and 1920, but it is my understanding that the system was characterized by four large groups:
- Republicans: a pro-business WASP-dominated group with its heart in the Northeast and the Midwest;
- Democrats: an unusual coalition of urban immigrants and white Southerners, united mostly by their antipathy to the Republicans;
- Progressives: largely Republican (though found in both parties), they were dedicated to fighting corruption and perceived abuses of power within a system characterized both by urban machine politics and the increasing economic and political power of large businesses; and
- Populists: a largely rural phenomenon, this grouping within the Democratic Party combined left-wing economic ideas with support for traditional religious and cultural values.
When you compare this picture to the situation today, you find some elements of continuity and some significant differences. The Republican Party of the 1890’s is essentially the PBP faction of today’s GOP. The Progressives are best analogized to policy wonks allied with Obama and Clinton within the Democratic Party. The Democratic Party of the 1890’s no longer exists; the closest modern analogy would be to ethnic minorities within the party (of course, African-Americans had no power at all in the First Gilded Age). Finally, today’s Populists can be found in both parties–they voted for Trump and Sanders. Based on the election results, you would have to say they are predominantly Republicans.
If there is a message here, it is that populism can’t easily be forced into traditional left/right pigeonholes. That is the heart of Trump’s message, and one of the reasons his relationship with the GOP elites is so fraught.