Chapter 15 + Liberty vote

Hey everyone!

I’m stuck at the voting part in Chapter 15.
I’m following the Recommended Route on PSNProfiles, and for the first playthrough I’m supposed to vote for Liberty, but everyone keeps sticking to their original stance.

I’m guessing I don’t have enough Liberty points to convince them properly.

What’s the best way to farm Liberty points?

Thanks in advance!

A slightly frustrated player