This post by Karim Doumar and Cynthia Gordy Giwa is a publication of Propublica. Here is an excerpt:

There’s a phrase that pops up a lot when investigative journalists talk about politics: Follow the money.

For journalists, that often means looking at how political campaigns are funded and who’s paying for lobbyists. Today we’re going to talk about some of the methods we use to dig into those subjects.

This advice may not lead to you uncovering large-scale corruption — let us know if you do, though — but we hope to better acquaint you with which industries are donating to races you care about, how your candidates spend the money they raise and the oversized influence the ultrawealthy can have.

Read the full article here.