You raise the capital. That’s how campaigns work. You start with a small office. Then you raise money to go bigger. Joe Biden wasn’t wealthy at all, yet he never lost an election, starting with the New Castle Counsel. Ocasio-Cortez didn’t have a ton of money. Look at Maxine Waters. Plenty of “poor” people get elected. You just have to be smart, organized and have a message. Certainly running for Senate or President isn’t easy, but local races are winnable which springboard you to higher office of you’re any good.
That’s a generic argument. You ignore that we’re talking about running against candidates who are favored by billion dollar businesses, and the people on the other side are not wealthy. Where can they ‘raise’ this capital from?