From ProPublica‘s Cynthia Gordy Giwa:

There’s a phrase that pops up a lot when investigative journalists talk about politics: Follow the money. It won’t lead you to uncover large-scale corruption (but if you do, please holler at us). It will get you better acquainted with which industries are donating to the races you care about, and how your candidates are spending the money they raise. Get more information like this by signing up for ProPublica’s User’s Guide to Democracy.

Money in politics gets a rap for being shady. But campaign finance isn’t just about the bad stuff.

For the times when it is, we have campaign finance laws. A quick history lesson: After the Watergate scandal (which, in addition to a break-in at the Democratic National Committee headquarters, involved campaign funds used toward the scheme), Congress passed a law requiring federal campaigns to report their political contributions and spending to the Federal Election Commission. This was designed as a check against corruption but also to empower voters and keep you reasonably informed about money in politics.

Let’s take a look at what money does in a campaign. Seeing where a candidate’s money comes from, as well as which groups are spending on behalf of (or against) their campaign, helps you understand their beliefs, the advice they’re getting and the kinds of policies they’re likely to support.

What does a donation get you?

If you’re a candidate… Receiving donations can help you win an election. It’s not the only factor, but by and large, donations get spent on the day-to-day expenses of running a campaign. Take a look at how your candidates are spending their funds this season here, using ProPublica’s FEC Itemizer.

It’s probably garden-variety stuff: lunch, plane tickets, campaign ads, hotel rooms and venue rentals for campaign events. The choices candidates make tell you something about their priorities: where they’re spending their time, which voters they’re trying hardest to win over (older voters with TV ads or younger folks online) and how much they pay their staff.

Of course, sometimes candidates try to get creative in describing their campaign expenses, like California Rep. Duncan Hunter, who, along with his wife, is under indictment for spending donations on family trips to Hawaii and Italy and private school for their children.

If you see something suspicious in your candidates’ spending, or have questions, let us know at itemizer@propublica.org!

If you’re a donor to a candidate… My colleague Justin Elliott recently reported on a major donor to Donald Trump, casino magnate Sheldon Adelson, who contributed $20 million to Trump’s campaign and an additional $5 million for inauguration festivities. Since then, the Trump administration has helped advance some of his financial interests. For example, Trump reportedly raised Adelson’s bid to build a casino in Japan during Prime Minister Shinzo Abe’s visit to Mar-a-Lago, and his tax plan included new benefits to companies like Adelson’s.

But this is not the norm.

Most of the time, campaign donors don’t see a “return” on their investment. If you donate to a candidate, chances are you’re getting one of two things:

1. The satisfaction of backing a potential winner.
2. Lunch. Or something like lunch, with a chance to share your perspective with the candidate once he or she has taken office.

Campaign donations are not supposed to be transactional — that’s considered bribery, and it’s a crime. But they are a way of establishing a relationship and opening the door to conversations between the donor and the government. This is why, for example, defense industry PACs give to candidates who sit on the Armed Services Committee. They have an interest in talking to the people who help govern their industry. Conversely, when Rep. Charles Rangel stepped aside from the powerful House Ways and Means Committee for ethics violations, his once-stalwart campaign donors disappeared because he no longer had an important role for their interests.

Yes, it’s murky.

But, thanks to the post-Watergate Congressional Class of ’74, we can at least see what’s behind the curtains. If you give $200 or more to a candidate, the campaign is required to report your name, address and employer or occupation to the Federal Election Commision. Based on these FEC filings, along with similar disclosures from political action committees, the Center for Responsive Politics (through their site OpenSecrets.org) determines which industries are funding the candidates in your race.

Take a close look at the types of sectors and interest groups donating to your candidates. These can signal who has their ear.

If you’re a donor to a super PAC… Mostly what you get are negative campaign ads. Some of the biggest players in the campaign landscape are super PACs. These are political action committees that don’t give directly to the candidate but spend independently in support of (or in opposition to) them. This outside spending is completely uncapped, freeing super PACs to raise any amount of money to influence any given race — typically for negative advertising. (You may balk at this, but, even if people claim to hate them, attack ads work.)

Think about the negative ads you’ve seen lately. Chances are they were funded by a super PAC, believing certain voters can be activated based on their message. Knowing who these groups are can help you better understand their motives (and better assess whether you buy what they’re selling). Here’s where you can find out more about independent expenditures in your state’s races.

Super PACs tend to represent three main categories:

• Single-Issue Groups: Think advocacy groups that focus on abortion, or the environment, or taxes.
• Partisan Groups: These are super PACs formed at the direction of key House and Senate leaders, like the Congressional Leadership Fund (affiliated with House Republican leaders) and the Senate Majority PAC (connected with Senate Democratic leadership). While lawmakers themselves are restricted from soliciting unlimited donations to the super PACs they’re tied to, the people running these groups can do so on their behalf.
• Family Interests: Basically, this is when a wealthy family member comes through (like Kansas House candidate Steve Watkins’ loaded dad).

Outside spending from super PACs can have a big impact on an election. ProPublica and Politico recently reported on Mountain Families PAC, a super PAC set up by allies of Senate Majority Leader Mitch McConnell to intervene in this year’s West Virginia Republican primary. The group spent $1.3 million against Don Blankenship, a former coal baron who was considered the wild-card candidate, in a three-way race. Blankenship finished third, and Mountain Families shut down in May. Mission accomplished.

Homework

ProPublica has a tool called FEC Itemizer, which lets you browse electronic campaign finance filings from the commission. Until very recently, Senate candidates kicked it old school by only filing these reports on paper. That changed on Oct. 15, and now you can use the FEC Itemizer to follow the money in your Senate race, too.

Stay up on how the midterm election is going for voters like you across the nation, check out the latest from Electionland.