I don't know which period the parent may be referring to, but if you believe in Mr. Monroe's methodology[0], you can definitely see the reduction in moderates o

I don't know which period the parent may be referring to, but if you believe in Mr. Monroe's methodology[0], you can definitely see the reduction in moderates on both sides starting at a peak around 1930. [0]: https://xkcd.com/1127/large/ https://xkcd.com/1127/large/