As a business major (concentration in finance), how difficult would it be to apply for political science co-ops? Do co-ops generally require or just recommend that the applicant is of a certain major?
It is up to the company - they specify what they want - some say which majors they prefer - some include long lists of majors they would accept. Your co-op advisor will make visible to you only those which include your major in their requirements (so as a nursing major you won’t even see jobs for engineers.)
You would have to make a case for yourself with your coop advisor. How would a poly sci coop fit into your career plans? For example you wanted to work on campaign finance reform.
Ultimately, it’s up to the company if they’ll hire you. But you have to be approved by the co-op advisor before your application will be sent to employers. (It’s to make sure they keep a good relationship with employers by preventing them from getting spammed with bad/unsuited applications.) You’d likely set up a meeting with the co-op advisor for poly-sci to discuss jobs and they could release your resume to employers.
I applied to engineering and computer science co-ops as a neuroscience major, so it’s definitely doable if the jobs are a good fit.