2,425 Precincts

Across the set, 86% of precincts shifted toward the Democrats between the 2024 presidential election and their 2026 special election, and only 14% shifted toward the Republicans. The most common size of shift was 10 to 20 points in the Democratic direction. Democratic candidates flipped 54% of the precincts Donald Trump had won by 10 to 25 points.

The engine is turnout. In Trump-won precincts, Democratic voters returned at 38.6% while Republican voters returned at 25.9%, a 12.7-point retention gap inside Republican territory. In Harris-won precincts both parties returned at lower rates, 26.2% against 18.9%, still a 7.3-point gap in the Democrats' favor.

Starting from a public tracker of every 2026 special election, I collected precinct-by-precinct results on election day, matched each precinct to its 2024 presidential result, and attached the generic-ballot average and presidential approval as of each election date. Precincts that had been split or whose registration had changed materially since 2024 were flagged and excluded, and a few elections had to be dropped entirely rather than compared unfairly.

The finished dataset holds the election date, precinct name, special-election votes by party, 2024 votes for Harris and Trump, and the national environment at the time. It is downloadable as a CSV from the article, which is republished in full on this site.

The piece is explicit about its limits. Special-election precincts and general-election precincts are not perfect comparisons, the set covers only races with published precinct results, and shifts of this size will almost certainly shrink in November. It is a measurement of what happened in 2026 specials, not a midterm forecast.