In 2015, well over half of the money contributed to the presidential race came from roughly 350 families. The 100 biggest donors gave as much as 2 million small donors combined. Can we still say we live in a democracy if a few hundred rich families provide a disproportionate shares of campaign funds? Congress and the courts are divided on that question, with conservatives saying yes and liberals saying no. The debate is about the most fundamental of political questions: how we define democracy and how we want our democracy to work. The debate may ultimately be about political theory, but in practice it is conducted in terms of laws, regulations, and court decisions about super PACs, 527s, 501(c)(4)s, dark money, small donors, public funding, corporate contributions, the Federal Election Commission, and the IRS. Campaign Finance: What Everyone Needs to Know? explains those laws, regulations, and Supreme Court decisions, from Buckley v. Valeo to Citizens United, asking how they fit into the larger discussion about how we want our democracy to work.