Context From The Talk
“When I was growing up, the Democrats were a left to center party, but they had a lot of moderates. They also had a conservative wing, mostly centered in the South, but not exclusively. Republicans were a right of center party, but they too had moderates and a liberal wing, mostly centered in the northeast. We now have a liberal lump and a conservative lump, and the middle is gone. The Democrats have pretty much shed their entire conservative wing. Republicans have pretty much shed their entire liberal wing. We have two clearly differentiated parties.
The sorting that's occurred has had a number of consequences. The first is, almost by definition, the parties have polarized much more than they used to.
The second consequence is that sorting has led to a re-nationalization of American elections. In the mid 20th century, people voted for the person and not the party. Now, they vote for the party. Individual candidates matter much less than they used to.
In this era, we have two highly polarized parties. Not the electorate, but the parties. They overreach. They respond to their base pressure, the people who basically, if you're a Democrat, your pressures are coming from the left. If you're a Republican in office, your pressures are coming from your right. To satisfy these base pressures, they take relatively extreme positions. They emphasize issues that are priorities of the base, but not priorities of the general public, that activists tend to often be motivated by things that are important to them, but not important to the electorate at large. This alienates marginal supporters, the people who say, "Well, I didn't really vote for that," once they get in office. There's also an electoral reaction. Because the parties are so closely matched, they just need to lose a few votes to lose the next election.”