The Know Nothings, of course, were an anti-immigrant nineteenth century American political party. For obvious reasons, they are frequently analogized to today’s GOP.
It is my understanding that some Republicans are attacking Biden’s cabinet choices on the basis that they are members of the intellectual elite, not proper populists. Leaving aside the fact that Trump frequently boasted about the Ivy League credentials of his appointees, that’s taking the concept of Know Nothing to an entirely new level.