This week, the U.S. Supreme Court took up a controversial case on whether a question about citizenship should be included on the 2020 census.

The White House says that adding the question will help enforce the Voting Rights Act. But opponents say that the real goal is to discourage mainly immigrants and Latinos from being counted, threatening congressional representation and billions in federal funds to local communities.

WGBH Radio's Isaiah Thompson has been digging into the possible local effects here in Massachusetts. He wrote about his findings for WGBHnews.org. Isaiah also spoke with WGBH All Things Considered anchor Barbara Howard. This transcript has been edited for clarity.

Barbara Howard: So first of all, to a lot of people, just adding the question “Are you a U.S. citizen?” seems like it's not such a big deal. Is there any evidence that this would affect the count?

Isaiah Thompson: Yes, there actually is evidence that this would, to some extent, cause a certain number of people, mostly immigrants and Latinos specifically, to answer the census in fewer numbers. And in fact, the Census itself commissioned a study that found that that response could be lowered by as much as 6 percent or more by asking a citizenship question. And that could have consequences.

I talked to Professor Andrew Reamer. He's heading up a project to track all federal funding linked in some way to the Census. He's a professor at George Washington University's School of Public Policy. And he says in some ways, it is kind of a zero sum game when it comes to funding. “If one accepts the scenario that non-citizen households are going to be less likely to fill out the census form then the states with a percentage of non-citizens higher than the U.S. average - which is 7-percent - will lose money and states below 7-percent will gain money," Reamer said.

Here in Massachusetts, about 17 percent of residents are immigrants, so Massachusetts would be one of those states that would lose money.

Howard: And even more so over time because that population is growing and the census is only taken every 10 years, right?

Thompson: That's exactly right.

READ MORE:5 Ways The US Census Dispute Could Affect Massachusetts

Howard: Well where are some other places Massachusetts could be short changed in the event of an undercount?

Thompson: So in Massachusetts, like pretty much everywhere else, the largest source of federal funding that is tied to the Census is Medicaid reimbursements. For reasons that are somewhat complicated, that is unlikely to be affected too much, because Massachusetts is a wealthier state. We already get reimbursed at pretty much the lowest rate. But there are other smaller programs that are really a lot more sensitive to a potential undercount in the Census. Those are programs like school lunch programs for children, nutrition programs for pregnant women, and housing assistance for low income people.

Howard: What about here in Massachusetts? Are there any unique challenges that make an accurate count more difficult?

Thompson: Yeah, so all around the country there are places that the Census officially calls hard to count places. And we have a number of those here in Massachusetts. Here, they tend to be denser urban areas: think Boston, Fall River, and Lawrence. Well, those are also the very same places that the highest concentrations of immigrants live in the state.

Howard: So an undercount could really be felt here.

Thompson: Yeah, it could have even more impact for those reasons.

Howard: All right. Well thanks for joining us, Isaiah.

Thompson: Thanks for having me, Barbara.

Howard: That's WGBH Radio's Isaiah Thompson talking about the ways that a citizenship question on next year's U.S. Census could affect federal funding here in Massachusetts. The U.S. Supreme Court is expected to come out with a ruling on the citizenship question in June.