Clarification: An earlier version of this editorial stated that congressional redistricting will take place in 2020. The census will take place in 2020, followed by redistricting that will affect the elections in 2022. This version has been updated.

IN HIS confirmation hearing last month, Wilbur Ross noted he may be the first secretary of commerce nominee who was once a U.S. census taker. Those skills could come in handy right about now: A recent report indicates the 2020 Census is in trouble.

Mr. Ross, who as a business-school student served the Census Bureau as an enumerator in Boston, is scheduled to see a confirmation vote next week. If it is a yes, he should get to work immediately, looking to the report published this month by the Government Accountability Office that includes the decennial among its list of “high risk” operations.

According to the GAO, the Census Bureau has announced a plan to replace its paper-and-pencil operation with smart technological innovations, but has yet to guarantee it can implement those changes successfully in 2020. The bureau scrapped some important 2017 field tests that could have helped answer that question because of uncertain funding. It also struggled with high nonresponse rates in 2016 tests, and cost estimates for the 2020 survey are shaky. All of that needs to change before it is too late for fixes.

There is a reason the Founding Fathers saw fit to make the census part of the Constitution: The national head count is critical to a functional democracy. Not only is it a vital research tool, but also the census determines how many seats each state gets in the House of Representatives and how district lines are drawn. Any doubt about the data’s validity could cause a crisis in the redistricting battle which will follow the census and affect the elections in 2022 — which is why it is essential that the bureau gets it right.

That has become a tougher (and more expensive) task in a society where living situations are getting more complex and heads harder to count. A steadier funding stream would help the Census Bureau conduct the tests it needs to make sure its new strategies work in 2020, but the GAO says it will take more than that to get the census back to good. The bureau will also have to strengthen its internal controls and communication . That will take careful oversight from Mr. Ross and thoughtful decisions about those working closer to the ground — especially with the current census director’s term slated to end next year and other high-level officials set to retire before the 2020 operation is complete, all amid a federal hiring freeze.

The census may be the most important thing in government that no one talks about. That the 2020 report could lack integrity would be worrying on its own, and it would be even more so under an administration that has repeatedly displayed a disdain for data. Saving the census would give Mr. Ross an early opportunity to prove that he, at least, cares about accurate numbers.