The dichotomy I’m talking about is one of Democratic = liberal/progressive and Republican = conservative.
Until recently both parties had liberal and conservative wings.
For the first time in about 1.5 centuries the top end pro-US Bank crowd are over in the Democrat party ~ I can hear Jackson rolling over in his grave.
TR's progressives gravitated early into the Democrat shell corporation ~ the business crash in the immediate post WWI period lost them the popular vote though ~ so you end up with a short string of Republican Presidents, another downturn, then 16 long years of leftist tyranny led by the same old progressives who'd blown it under Wilson.