THE CONSTITUTION OF THE UNITED STATES sensibly requires that we “count the whole number of persons in each state” every 10 years. The results of the census are used to determine representation in Congress, and therefore the number of Electoral College votes each state gets. It is also used to allocate federal funds for, among other things, education, transportation, housing, and public health. Many people may find the topic a little dry, but I don’t. Making sure the United States Census is conducted fairly and accurately is a really big deal. That has always been true, but President Trump’s anti-immigrant sentiment, rhetoric, and policies now include a proposal to include a question about citizenship status on the 2020 census. This is wrong. It’s not only unconstitutional, it would make it harder for us to govern. Trump’s motive is plain and painfully clear: he is trying to sabotage the census

The Constitution stipulates that “persons” be counted, not “some persons.” It means you, me, and all our neighbors, regardless of immigration status. In Massachusetts, we have approximately 6.8 million residents, including about 500,000 immigrants who are here legally, and about 500,000 who are undocumented. That’s 1 million people who should be, and need to be, counted when we conduct the next census for 2020. If we can’t count our immigrant communities, cities like Lawrence and Springfield, with both high immigrant populations as well as high needs for federal funding, will lose out. The socio-economic ripple effect will be felt across the Commonwealth.

I served as census liaison in 2000 and 2010, and I saw hurdles we needed to overcome to build trust in some immigrant communities to encourage them to participate. To address that, we reached out to groups in those communities, everything from social clubs to sports teams. Every time we conduct the census, we discover new communities using languages we had not needed to translate before, and we have found a way to reach them. We have worked with local public schools to find out which languages their students are speaking at home, so that we know which languages their families use. I am the designated Census Liaison for 2020, and I’d like us to be able to reach out and engage with our immigrant communities the same way we always have. If Trump’s policy is implemented, we won’t be able to, and it will have a chilling effect upon our immigrant communities that goes far beyond the census count. Immigrants already justifiably fearful of ICE arrests and other immigration enforcement actions may be less willing to engage with state officials than ever before. What we have been able to do in the past to build trust and encourage participation will, like the census, be sabotaged.

On that basis alone, all of Massachusetts, including our immigrant communities, will lose out under the 2020 Census if Trump’s policy is allowed to stand. But another enormous risk is that we could lose a seat in Congress. Without including our immigrant population, the number of our US representatives could be reduced from nine to eight. It is western Massachusetts where we are most likely to lose a seat, leaving the largest geographic area of the Commonwealth with the smallest number of US representatives.

That’s why, when Trump’s proposals were first suggested in March, I was the first secretary of state in the country to speak out against them. I said we should sue if they were not reversed. Shortly thereafter, Massachusetts Attorney General Maura Healey joined a coalition of attorneys general and cities to sue the Trump Administration. Early this month, the lawsuit was allowed to continue. The federal judge hearing the case found “strong” evidence that the Trump Administration acted in bad faith, and ordered the administration to provide critical information to determine why the citizenship question should be inserted and what the implications would be.

This is encouraging, and I am hopeful. But I know from past experience what the grave consequences of losing this lawsuit would be. The US Census should not be politicized. The Trump proposal is clearly designed to hurt states with high immigrant populations and which are likely to elect Democrats to Congress, such as Massachusetts, California, and New York. The US Constitution requires that everyone be counted because without knowing exactly who we are, the government cannot know how to govern. We must be able to count “the whole number of persons” in the Commonwealth.

Everyone in Massachusetts needs to be counted, including everyone in our immigrant communities. I want all of us to be able to trust our census workers, regardless of our own immigration status. We will not report you. We will not turn over any information about you to the federal government or anyone else. We are there because everyone has a legal right to be counted, and when we know where you are and how many of you there are, we will be able to serve your communities and our Commonwealth much better. You have a constitutional right to count on that.

William Galvin is the Massachusetts secretary of state. He is being challenged in the Democratic primary by Boston City Councilor Josh Zakim.