The ACLU claim to be non-partisan and crucially actually put their money where their mouth is. The ACLU has defended:

• The KKK (https://www.aclu.org/news/aclu-em-defends-kkks-right-free-sp...)

• Neo-Nazis (https://www.aclu.org/other/aclu-history-taking-stand-free-sp...), something their history page refers to as "our finest hour"

• Milo Yiannopoulos (http://www.npr.org/2017/02/12/514785623/the-aclu-explains-wh...)