As planning for the 2020 census hits the advanced stage, area members of Congress are increasingly worried about whether the count will be as full and complete as it ought to be.

In a letter today to U.S. Census Bureau Director Steven Dillingham, all 15 Democratic members of the state's Washington delegation expressed "concern" about the status of preparations for the big count and asked for an update on what's being done—especially for hard-to-reach groups such as low-income households, people of color, immigrants and the homeless.

"Illinois stands to lose at least $1,800 a year for each person who goes uncounted—for a full decade," states the letter, which is signed by Sens. Dick Durbin and Tammy Duckworth and 13 members of the U.S. House. "With administrative and technological changes being made to the upcoming Census, the bureau must provide Illinois with the necessary resources to count all Illinois residents."

The bureau had no immediate response, but it has a prescheduled national conference call with reporters this afternoon.

The letter comes after a fight that went all the way up to the U.S. Supreme Court over whether to add a question about citizenship to the census. In a 5-4 vote, the court sided with Democrats and officials from states with large immigrant populations that the Trump administration had not provided adequate justification to add the question late in the planning process.

In their letter, the members expressed the greatest concern over whether the bureau will have and fund a "physical presence" in the state, rather than merely relying on the internet as the primary way to obtain responses.

It specifically asks about the opening of area census offices and whether there will be as many as a decade ago, whether the bureau will work with public libraries and other "trusted" organizations to answer questions, how many staffers it is hiring here and who will be in charge of the Illinois count.

Perhaps anticipating that the Trump administration is not eager to count certain groups, both the city and state have stepped up their efforts to enhance the count, though some activist groups are urging even stronger steps.

At stake in the census is not only some federal aid that is distributed on a per capita basis but how many congressional districts the state will have—as well as how state legislative and Chicago City Council seats are remapped.