WASHINGTON -- The Trump administration is being sued over its plans to include a question about citizenship in the 2020 Census, which California Attorney General Xavier Becerra (D) says "is not just a bad idea - it is illegal."

No, it's not. There is nothing wrong with asking about citizenship. Canada asks a citizenship question on its census. So do Australia and many other U.S. allies. The U.S. government asked about citizenship for 130 years - from 1820 to 1950 - as part of the decennial "short form" census and continued to do so in the "long form" survey - distributed to 1 in 6 people - through 2000, when the long form was replaced by the annual American Community Survey. The ACS goes to about 2.6 percent of the population each year and asks about citizenship to this day.

So why are many on the left up in arms over a question that should be relatively uncontroversial? Answer: Money and power. Democrats are worried that adding a citizenship question will dampen participation in the census by illegal immigrants, reducing the total population count in the Democratic-leaning metropolitan areas where illegal immigrants are largely concentrated. Because census data is used to determine the distribution of federal funds, that could decrease the cities' share of more than $675 billion a year in federal funding. And because census data is also used to create and apportion congressional seats, Democrats fear that if illegal immigrants don't participate it could shift power from Democratic cities to rural communities, which tend to vote Republican.

At least, that's Democrats' theory. But there is no evidence that a citizenship question would dramatically impact census participation. The census is not like a telemarketing survey where people have the option of adding their names to a "do not call" list. Everyone is required by law to respond. If a household does not fill out the census form, then census workers visit that household to gather census data. If they still cannot get a household to cooperate, nonrespondents can be fined or prosecuted - though in practice they rarely are. Usually, the Census Bureau instead asks neighbors about the household in order to get as much accurate information as possible. This may add costs to the census, but it is not likely to produce inaccurate data.

Moreover, if asking about citizenship is a deterrent to participation by illegal immigrants, then what about the existing census question that asks whether respondents are "of Hispanic, Latino, or Spanish origin" - the only ethnic group specifically called out. Respondents are required by law to tell the government whether they are of Mexican, Puerto Rican, Cuban or other Hispanic origin, which they are required to list ("print origin, for example, Argentinean, Colombian, Dominican, Nicaraguan, Salvadoran, Spaniard, and so on"). If that does not deter the participation of many illegal immigrants, how would a question on citizenship?

There is no good reason not to answer the census, whether one is here legally or illegally. As the Census Bureau points out, "It is against the law for any Census Bureau employee to disclose or publish any census or survey information that identifies an individual or business .?.?. the FBI and other government entities do not have the legal right to access this information." Furthermore, the proposed question is about citizenship, not legal status. This question should not be a deterrent to participation for anyone.

But let's say for the sake of argument that some illegal immigrants do decide not to participate in the 2020 Census. So what? Illegal immigrants are here illegally. If they choose to violate U.S. law yet again by refusing to participate in the census because of a perfectly legitimate question about citizenship, that's not the U.S. government's fault.

This is a losing issue for Democrats. They are effectively arguing that sanctuary cities should be rewarded with more federal money for interfering with the federal enforcement of our immigration laws and turning themselves into magnets for illegal immigrants. And Democrats, who claim to be deeply concerned about foreign interference in our democracy, seem to have no problem with foreign interference when it comes to noncitizens in the United States illegally affecting the distribution of seats in Congress. If Democrats want to make that argument to the American people, go for it. It will further alienate millions of voters who abandoned the Democratic Party in the 2016 election.