“It’s well-established at this point that, while both parties have gotten more ideological in recent years, the Republicans have gone way further off the deep end than Democrats. This “asymmetric polarization,” an aftershock of the post-civil rights political realignment of the South, means that Republicans are significantly more likely to nominate “extreme” candidates than Democrats are. Hall’s research suggests that this could ultimately erode the Republican advantage in the House.”
This all follows with the literature on polarization, but here’s the key to why political polarization will continue to be troublesome.
…gerrymandering creates a glut of “safe” Republican districts, then Hall’s extremism penalty won’t end up being much of a penalty at all.