By Wendy Underhill

Redistricting data will be available to the states in the last half of August. That’s the latest news from the U.S. Census Bureau, and it didn’t get the attention it deserves, so let me say it again: Redistricting data will arrive in late August, which means redistricting can start soon thereafter.

Think of the data release as the bell sounding at a horse race—until then, states are under starters’ orders in their starting stalls. The data in question is the granular, census block data, known as the “P.L. 94-171 data” or just the “PL data.” It provides states with information on the total population and voting age population at the smallest geographic level (a census block), broken out by dozens of race and ethnicity combinations.

By federal statute, the PL data was due to the states by April 1, 2021. As winter wore on, it became clear that delays were inevitable due to the pandemic and other factors. On Feb. 12, the bureau announced a new release date: by Sept. 30. While a full six-month delay was shocking, many in the redistricting community heaved a sigh of relief because they had a fixed date to plan on.

But not everyone responded with relief. The attorney general in Ohio, Republican Dave Yost, responded with a lawsuit, Ohio v. Raimondo. The suit demands the data be released on the existing federal schedule, given that the bureau has received no waiver from the April 1 deadline. In response to that case, bureau staff prepared various declarations, and in so doing they realized that by the second half of August they would in fact have all the PL data in hand—and could release it.

The data will be exactly the same as what will be released in September. That means redistricting’s bell goes off five months late instead of six months late, begging the question: what’s the difference between data released in August and that released in September?

The August release will give the states the full PL dataset from which data professionals can extract the relevant data for their redistricting software. By September 30, the same data will be released in a user-friendly tabular format. Read all about it in the bureau’s March 15 press release.

States have the expertise to do what needs to be done with the August dataset. Redistricters are the “first responders” on the census scene, says Clark Bensen, of Polidata. “They take no more risk upon themselves this decade than they did in the previous decades,” when the August-style release was also an option.

So, one more time: redistricting data arrives in August and redistricting starts soon after.