Late last month, my office and the American people received great news from the White House: our petition to reinstate the citizenship question in the decennial 2020 Census was approved. We will once again get a more accurate count of how many American citizens reside in our country.

As the chief legal officer of Louisiana and a former member of Congress – I know how critical the data concerning citizenship, legal immigration, illegal immigration, and the distribution of the population is to the functions of government. It is also crucial in terms of ensuring fair and equitable districting of the people’s representatives at the State and Federal levels. This issue touches the heart of our republic and the constitutional rights of every citizen.

The decision by Secretary of Commerce Wilbur Ross to ask if one is a citizen or not is no new idea. For decades, the Census Bureau included a citizenship question on the “long form” questionnaire sent to nearly one in every six households during each decennial census. The long form’s replacement – the American Community Survey – also collects information regarding citizenship and estimates citizen voting-age population, though its estimates have a much higher margin of error since it is sent to far fewer people.

The move by Secretary Ross is important because States generally apportion their legislative districts based on census numbers. Counting everyone regardless of legal status dilutes the votes of all legally-eligible voters by not only bolstering the representation of illegal immigrants and non-voting legal immigrants at the expense of the voting age citizenry, but by also skewing the national data and some States losing Congressional representation.

Furthermore, the reinstatement restores the rule of law. The Supreme Court has held that Section 2 of the Voting Rights Act prohibits “vote dilution” by state and local jurisdictions engaged in redistricting, which can occur when a racial group is improperly deprived of a single-member district in which it could form a majority. Multiple federal courts of appeals have held that, where citizenship rates are at issue in a vote-dilution case, citizen voting-age population is the proper metric for determining whether a racial group could constitute a majority in a single-member district.

This more accurate decennial census could prevent the inevitable dilution of votes and the further exposure of states to endless litigation as courts have reasoned that “the right to vote is one of the badges of citizenship” and that “the dignity and very concept of citizenship are diluted if noncitizens are allowed to vote.” Thus, it would be the wrong result for a legislature or a court to draw a single-member district in which a numerical racial minority group in a jurisdiction was a majority of the total voting-age population in that district but “continued to be defeated at the polls” because it was not a majority of the citizen voting-age population.

When the right of all citizens to cast a properly weighted vote is not protected, there is a resulting dilution of the voting power of citizens residing in districts that are home to a smaller number of nonvoting residents. Moreover, it incentivizes sanctuary cities by granting an electoral advantage at the expense of non-sanctuary cities.

Voting is one of the most precious rights of citizenship. I am grateful the Trump Administration is working to protect it.

Jeff Landry is the elected attorney general of Louisiana and a former U.S. representative.