Next month marks the 40th anniversary of the Watergate break-in. But the burglary was the tip of the iceberg: the bigger scandal involved President Nixon’s 1972 re-election campaign brazenly peddling government favors for millions of dollars of political donations. In Watergate’s aftermath and the decades since, Congress strengthened our campaign finance laws. But the Supreme Court has chipped away at those reforms, making it harder to fight the corruption that flows from money in politics. Supreme Court missteps, compounded by lower court decisions, have produced the current anything-goes campaign environment. The Court now has an opportunity to undo some of the damage. It is considering a request to take up a case out of Montana that could clarify how much leeway the government has to regulate corrupting political money. Understanding why the Court should do so requires looking at where we are — and how we got here.