Massachusetts Attorney General Maura Healey co-wrote a multi-state letter urging the U.S. Commerce Department not to include a question about citizenship on the U.S. census in 2020.

"The census is supposed to count everyone. This request by the Trump Administration will result in an undercount of the Massachusetts population and threatens federal funding for our state and our cities," Healey said in a statement.

The Department of Justice has proposed adding a citizenship question to the census. The Department of Justice letter, first reported by ProPublica, said that in order to protect against racial discrimination in voting, the department needs a reliable count of the voting age population in places where discrimination is suspected. Between 1970 and 2000, a citizenship question was included on the "long-form" census form, which was sent to one in six households. In 2010, that census form was replaced with a survey that was sent to fewer households.

Opponents of adding a question say it will discourage participation in the census by immigrants, those who entered legally and illegally. The census is required by law to count every person living in each state, regardless of legal status.

Healey co-authored a letter to Commerce Secretary Wilbur Ross with New York Attorney General Eric Schneiderman and California Attorney General Xavier Becerra. They were joined by 16 other attorneys general and the Colorado governor.

The letter urges the Commerce Department, which oversees the census, to reject the Department of Justice's request.

"Adding a citizenship question -- especially at such a late date in the 2020 Census planning process -- would significantly depress participation, causing a population undercount that would disproportionately harm states and cities with large immigrant communities," the attorneys general wrote.

They wrote that this could jeopardize federal funds that are allocated based on population and skew representation in Congress and the Electoral College.

The attorneys general argue that the Census Bureau has long recognized the difficulty of getting immigrants to respond to the census, and that difficulty is likely to increase in 2020 as immigrants are more worried about confidentiality due to President Donald Trump's rhetoric and actions on immigration. Adding a question on citizenship, they said, would likely decrease the rate of response by immigrants and increase the number of inaccurate responses.

They wrote that there is also not enough time to properly test the questions, since the final census must be provided to Congress by March 31. In addition, the Census Bureau is underfunded, and adding a citizenship question could make it more expensive if census officials have to track down more individuals who do not return census surveys.

They argued that collecting citizenship data would not help voting rights, but would harm them, if communities are underrepresented.

Secretary of the Commonwealth William Galvin, whose office administers the federal census, has been outspoken against the addition of a citizenship question, calling it a political play by the Trump administration to "sabotage" the census in states like Massachusetts that have large immigrant populations.

"To count everyone, whether legal or undocumented, that's always been a challenge," Galvin said. "The problem now, in light of the rhetoric of the Trump administration, is going to be even more so. Adding this question would only add to the confusion."

All cities and towns in Massachusetts send out annual surveys to every household asking for verification of who lives there. The survey includes a question about nationality.

But Galvin said the Massachusetts questionnaire is different from the federal census. The annual listing of residences is sent out by communities to keep their voter lists current. The citizenship question is necessary, because only citizens are allowed to vote. The listing is also used to establish jury pools, which are also dependent on citizenship.

The national census is different, because its purpose, under the Constitution, is to count every person who lives in the U.S.

Galvin praised Healey's decision to write the letter. "It's the right thing to do," he said.

He noted that work is ramping up now to prepare for the 2020 census.

Multi-State Letter Re 2020 Census by Anonymous V8Ihswp4nM on Scribd