How do you get political points?

certain missions give them as rewards.

Spoiler below. Select the text to view.

The only mission I have so far that gives Political Favor is "Dangerous Mission". It doesn't show any requirements, so it must be a level-based mission. If you haven't got access to it, then you're not a high enough level yet. I'm level 67, but I know i've had this mission available for quite a while, so it probably becomes available around level 50-60. There's bound to be further missions that give Political Points too.

People in your Legion can also give their Political Favor to you, but I doubt anyone would actually give them as it means they can't use them themselves, then. Political Favour are displayed in the "Special" section in the trade screen, but they do NOT take up Cargo space.

End spoiler.

IM 39 and have had that mission for quite a while, i would say you get it around 20-30 even

Hmm i've had it longer than I thought then.

By the way, you can make text invisible with colour #313131.

there are two more I know of both are high risk but give a good amount of it. You may be limited in how much favor you get but unless your building 3 of those buildings on every planet. your not going to run out.