> In the US the way to influence politics is campaign contributions to politicians.

I mean, the US has a ton of industry funded "think tanks" that are effectively unregistered lobbyists. If they spend >50% of their time lobbying, they have to register. Some probably cross that line and don't register.

Spending money on lobbying makes a lot of noise, but donating to a "think tank" can be stealthy.

It could be interesting to scrape / crowd-source the public calendars of house/senate committee members and agency commissioners to identify these orgs and the scale of their lobbying activities. The results might surprise you.