Some Republicans in Congress are calling for cuts to the Census Bureau’s budget that would impair the agency’s already strained ability to gather basic data.

An accurate census is essential to determining the correct number of representatives from each state, the effectiveness of voting laws and the allotment of federal aid to states. In fact, information from the census and other surveys by the bureau is crucial to anyone — policy makers and businesspeople, researchers and citizens — who wants to understand the United States, assess where it is headed and influence its course on the basis of hard data.

The White House has requested a slim $1.5 billion for the bureau for fiscal year 2016. Much of that would be for the 2020 census, the planning of which is already behind schedule because of previous budget cuts. Next year is critical for the testing of data-gathering technology; Congress’s failure to provide timely financing to try out hand-held computers before the 2010 census forced a last-minute reversion to paper forms, which proved costlier than an orderly roll out of the computers would have been.

Congress looks set to make the same mistake again. At a recent hearing on the census budget, the Republican leader of the House appropriations subcommittee, John Culberson, indicated that spending on the 2020 census should be less than the total for the 2010 census. That makes no sense. In addition to upfront costs for technology, an adequate budget has to account for 10 years of inflation and population growth.