Crystal Mason spent the midterm elections glued to the television in federal prison in Fort Worth, Texas.

Two years earlier, Mason mistakenly voted while on supervised release for a felony conviction, and the punishment was severe. She was sentenced to five years in state prison in March, not including 10 months in federal prison because she violated the terms of her supervised release.

Mason’s case sparked national outrage because of the severity of her sentence. But it also underscores a larger point about who we allow to vote in America. Blocking people like Mason from voting isn’t just about stripping their political power — it’s about exiling them from the core of our community.

In “Shut Out,” a new three-part podcast from HuffPost, we look at the many different ways officials nationwide exclude people from voting. How do politicians justify these kind of restrictions? And in a country where we believe that everyone has an equal say in democracy, why are we so willing to accept these barriers?

As America prepares for the 2020 election, the fight over voting is going to get nastier. In Wisconsin, Republicans stung by statewide losses moved to cut early voting just this week.

As this fight escalates, it’s important to understand that this battle isn’t new. That’s why we created this podcast. We explore the history of voting rights in America, and how that history informs current policies. There is a throughline from that history to Crystal Mason sitting in prison today.

All three episodes drop Monday, Dec. 17. Subscribe wherever you listen to podcasts.