Are Mid-Century Homes Historic?

The neighborhood next to might, Hyde Park in Austin, is currently in the process of becoming a historic district. There's some debate on this issue as well as about when "historic" homes are:

Hyde Park's application lists 480 [historic] properties, though some neighbors have questioned whether all of them — such as ranch homes from the mid-20th century — truly have historic merit.

I have to assume that most people reading this blog think mid-century ranch homes are historic and worth saving. And as someone who lives in a mid-century home and on a street comprised largely mid-century ranches (rumored to all be built by the same architect), I'm in agreement. It will be interesting to see if the city of Austin is of like mind.