You make a good point there.
Especially the part where both the Republican AND Democratic Party have being playing with right-wing populist extremism and tried to use it to their own advantage.
http://www.politico.com/story/2017/10/06/gop-primaries-chaos-democrats-243487
Once both parties are trying to cultivate right-wing populism, you can only do it so many times until you get to a stage where the GOP is hard right and increasingly small tent while the pencil pushers in Washington act flabbergasted and wonder how the GOP went "off the rails".
One of the lamest attempt at "both sides do it" I've seen in a while.
The Republican Party is responsible for their trash, let's not get it twisted. People like Mitch McConnell cynically decided that political extremism was a winning formula for defeating President Obama and taking back control of Congress, and with giant heaps of money at their disposal, they took their wins in 2010 and made all of their majorities indestructible via redistricting. Now they have no reason to appeal to the middle, so they run further and further to the right to win primaries. With all these factors, you eventually get a Republican Party spearheaded by demons like Donald Trump, Steve Bannon, Roy Moore, etc.
