Open borders is also a movement among international socialsts.
Fair enough. I'll admit to at least the possibility of some confirmation bias or observer effect or the sort here: While I do go out of my way to avoid echo-chamber silliness I've never heard (here in the US) of the open border movement outside of libertarian circles.
A response essay written by Eliezer Yudkowsky posted at Cato Unbound for the issue Brain, Belief, and Politics:
Is That Your True Rejection? by Eliezer Yudkowsky
The lead essay has been written by Michael Shermer:
Liberty and Science by Michael Shermer