This is an awesome guide—thank you for writing it, Jamie and Animal Advocacy Careers!
Below are some relevant links—though these are mainly focussed on the UK.
UK political party animal groups:
https://www.conservativeanimalwelfarefoundation.org/
http://www.labouranimalwelfaresociety.org.uk/
https://gap.greenparty.org.uk/
Other UK political parties may have similar sub-groups, too.
I’m not sure whether similar groups exist in other countries. (If not, maybe setting them up could be a high-leverage intervention?)
There’s also a UK political party for animals—the Animal Welfare Party: https://www.animalwelfareparty.org/
General 80k blog post on UK political careers—short and sweet:
https://80000hours.org/2016/01/10-steps-to-a-job-in-politics/
A careers guide for policy/politics jobs (mainly relevant to the UK):
Applying this logic one stage earlier in the process, one of the key things for EAs who are 15/16/17 to do, in terms of career planning, is to work very hard to try to get into a prestigious University (ie Oxbridge in the UK, Ivy League in the US). Doing so will:
help you get a great education
surround you with clever, highly-motivated people
give you a strong credential which will help you throughout the rest of your career, in terms of getting jobs and maximising your earnings.
It’s a peculiarity of the UK education system that in many respects, your *mock A-levels* are plausibly the most high-stakes exams you will ever take, because they influence whether you will get an offer of a place at a top University. Your decisions at age 16⁄17 can have very profound effects on the rest of your career, and from a lifetime perspective, it’s rational to ‘frontload’ a bunch of effort, focus, and willpower to try to get into a top University.
(It’s important to add, of course, that you can enjoy massive impact and success without getting in to one of the most prestigious Universities.)