"change the [laws]"... in 'murica, of all countries. No way unless you happen to have a couple of million $ lying around somewhere to bribe...eh finance the campaign of a politician.
Bullshit. It takes hard work, but ordinary people can get out there and do things just fine if they actively work at it rather than just whining on online forums.
Most of the marijuana legalization stuff isn't being driven by huge corporations.
Gay marriage rights are not a campaign that some lobbyist cooked up.
In my home state of Oregon, they legalized euthanasia a number of years ago. That wasn't exactly something with massive corporate backing... "Wash down that lethal dose of barbiturates with a refreshing Coca Cola!"
Gay marriage, pot legalization and crime-victim laws don't hurt anyone's profit (or, in case of crime-victim laws, the cost of opposing the law is higher than the cost of letting it pass) so there are no well-funded adversaries trying to kill these laws for profit.
This is the No True Scotsman fallacy. It's especially egregious given how well-funded opposition to gay marriage actually is. But even if we were in an alternate reality where the evangelical right (and the institutions that prey on them) weren't bankrolling enormous fights against gay marriage, the point you're trying to make would still be fallacious.
Hard work and a lot of time. Ordinary people putting in large numbers of unpaid hours of work competing against highly paid lobbyists that wine and dine with the elite.