I think the FSF bent of open source is easier to identify as explicitly political because it tries to force developers to do something they may or may not want (disclose source code). There's some anti-corporate messaging there, because it's hard to make money from software if it's free[0], and that's a political view others may not share.

[0] I do know the suggestion to sell support for software rather than selling software itself but that's a political view as well, trying to persuade businesses to earn money one way rather than another.

The Open Source name was specifically invented to distance itself from the polarizing political aspects of the Free Software movement.

https://www.gnu.org/philosophy/open-source-misses-the-point....