I'm not sure I'd describe the Carnegie Institution, or Rockefeller Foundation, who funded a lot of the eugenics research with the end in mind as notably liberal progressive. Nor could the Republicans Coolidge ("Nordics deteriorate when mixed with other races") and Hoover, who were both heavily in favour, be described as progressive liberals. Roosevelt was in favour too, of course.

It was a movement independent of politics, and especially popular in pre-war USA on both sides of the political divide.