Susie Cagle is one of my favorite journalists, so I was excited to work with her on ProPublica Illinois reporter Mick Dumke’s coverage of the Illinois Policy Institute and its affiliates. The stories show how the conservative think tank is part of a complicated web of business and personal relationships as it tries to influence state politics.

We believed illustrations could convey some of these relationships with clarity and nuance. I asked Susie to tell us more about her work and approach to the story we published this week — about the institute’s ties to an affordable housing debate on Chicago’s Far Northwest Side — as well as the series as a whole.

Why illustrations? And what led you to make a career using them as journalism?

I was a “words” journalist until I was laid off at the end of 2008, along with so many others working in media. I saw the shift toward digital media as one also toward visual media. As the industry changed, graphics teams bore the brunt of shrinking budgets, and I suspected that journalists and editors would soon realize that this was terribly shortsighted. So I bet on pictures. I taught myself how to draw, and began combining it with my reporting and writing. As the popularity of data visualization grew, I found a tiny foothold for comics journalism, too.

What do you think visual journalism can do that words can’t, and vice versa?

Editorial illustration is too often a production afterthought, and not a substantive part of the way a story is presented to readers. Illustrations are nice to look at, of course, but my interest in visual journalism is more in telling stories differently than decorating the words. It’s particularly useful to clarify complex systems and transactions, and represent people, places and interactions more economically than you might be able to do with text alone. There’s also a wild card element of empathy — we tend to identify more with a simplified illustrated face over a photograph of a real person — that can draw readers in and help keep their attention. And on that point, it’s also a very useful tool in telling stories with anonymous sources, while still humanizing them.

But illustration is a medium like any other, and there are a whole host of ethical pitfalls to contend with. For example, I spend a lot of time making sure the facial expressions I draw aren’t misleading, which isn’t something you have to worry about in words (though it’s certainly a concern for photojournalists).

How did you approach the story we published this week, where the illustrations aren’t just decoration but are part of the storytelling?

When I report and illustrate my own work, I’m thinking about the words and the pictures at the same time — which works best to communicate each piece of information, and how each element fits together to tell the clearest and most accurate story with the best aesthetic rhythm. I generally highlight major drawable elements from the outset, such as any elements in need of important context and explanation, big important numbers and people, and key scenes or moments of dialogue.

I really appreciate the vision of the editors at ProPublica Illinois, who brought me in to work on this story in the middle of the reporting process. It can be a struggle to find the most elegant way to include illustration if I get involved after a piece is finished. And Mick Dumke’s great work made my job easy here. There was a clear and consistent cast of characters, a complex web of transactions, and an overarching theme of money changing hands that made for a strong visual metaphor to lead off the first piece.

You’ve illustrated a couple of stories about this issue for us. How do you think about illustrations in terms of a series of stories?

That consistent aesthetic is nice-looking, of course, but it also helps to keep the series connected. Creating touchstone illustrated elements for a long series is perfect, as you can keep coming back to them again and again, and readers come to know your characters more clearly when associating them with those more simplified caricatures.

What are the little details that a reader might not consciously notice but help your illustrations tell the story?

I don’t really pride myself on my artistic license in this line of work, to be honest. But here are a couple: For the second piece in the series, I knew I wanted to assemble the people and organization panels together to lead off the story. I think that wide comic gives a sense of an almost overwhelming amount of complexity — so many people! so many doings! — which is a running theme through these pieces. And the through-line of the mint green money color background is probably my favorite touch.