- Opinionated - they believe in protecting or creating something.
- Motivated - they are not just an armchair critic - but willing to do something.
Bad things that are good to have
- political allegiance - most non-wealthy people who enter successfully have lifelong allegiance to one of the existing parties. - deep partisans succeed were moderates fail.
- backers - being part to an industry, ethnicity, union, religion, or advocacy group that supports you.
- No family commitments - politics quickly becomes life consuming for those involved.
- Money - obviously if you have to support yourself or your family while you are doing politics you don't have much of a chance.
Unfortunately most of the people who get involved don't stay involved, and the fraction of those who try