There is very little upside, and big downside risk. Unless you are sending resume to to apply for a position where you know for sure your political activity is a bonus, just don't mention it at all.
For hiring manager, first round of reading resumes is to eliminate as many CVs as possible as quickly as possible, to focus on important ones. All information in your CV should have the only goal: increase your chance to get an in-person interview, to be able to sell your skills.
When interviewing for specific position, you can research the company and decide if your politic principles are compatible with theirs, or if no compromise can be made.
Don't even mention any negative info like delay in graduation because of political activity. Goal of CV is not to explain glitches: it is to get you in-person interview. Instead, be prepared to deal with any glitches in personal interview by rehearsed phrases like "it took more time for certain personal reason, which were resolved and will not repeat". Done.
You want to be hired to solve work-related problems. If you are not talking about how your skills can solve problems for company, you are wasting time. Generic positive activity which you do in your free time is OK as icebreaker, but it will not get you hired. As I said, it has no upside.
Another take: put it in CV ONLY if you want to talk about it in interview. Valid for skills you have but don't want to develop more, or political activities.
Edit2: In comments below, OP answered his own question: he is aware that even for people who are not his political opponents, just the level of his dedication for a political cause might be a reason to toss his resume, even if hiring manager does not selected a side in that political issue. Which was my point all the way.