Texas Electoral Shift Atlas

Returns: Texas Legislative Council precinct-level (VTD) general election returns, 2016–2024, from the Capitol Data Portal, aggregated to counties and to each district plan. Boundaries: TLC district plans PLANC2100, PLANC2193, PLANC2333 (congressional); PLANH414, PLANH2316 (state house); PLANS172, PLANS2168 (state senate); and 2024 VTDs dissolved to county. The 2025 mid-decade redraw was congressional only — the 2021 legislative maps still govern 2022–2026.

District aggregation: whole precincts are assigned to one district by representative point, so districts that split a precinct carry a small allocation error. Checked against TLC’s official per-district 2024 turnout, all 31 senate and all 150 house districts landed within 1.5% (mean 99.5% of official ballots cast, consistent with the presidential undervote). Votes-needed model: arithmetic on past returns, not a forecast — it holds the electorate at the chosen turnout scenario and reports the net switchers, or the one-sided new votes, that a target margin implies. PDF report: generated in your browser from the view on screen; no data leaves the page. TLC notes small differences from official canvass; certify against the Secretary of State.

Primaries: 2016–2024 primary and runoff returns come from the same TLC precinct-level files, with party turnout taken from the accompanying voter-registration/turnout (VRTO) tables, so the turnout rate is ballots cast as a share of registered voters. The March 3, 2026 primary and May 26, 2026 runoff are unofficial: TLC has not published 2026 precinct data, and the Secretary of State posts only per-county canvass documents with no bulk export, so county totals were compiled from txelectionresults.com and cross-checked against AP, NYT and published race reporting (agreement within roughly half a point). Because that source is county-level only, 2026 primaries cannot be shown by congressional district; La Salle County was not reported and is blank. 2026 primary turnout uses top-of-ballot U.S. Senate votes as a stand-in for ballots cast, and 2026 registration totals are not yet published, so no 2026 turnout rate is shown. Certify all 2026 figures against the Secretary of State canvass before use.

Built and published by North Compass Political LLC. The primary turnout index is Republican minus Democratic primary ballots as a share of all primary ballots cast — a measure of which party’s primary a county participates in, not of how it votes in November. Primary shift compares each cycle to the comparable cycle four years earlier (presidential to presidential, midterm to midterm). Crossover is the primary index minus the same year’s general-election top-of-ticket margin. Contested-primary maps show the two leading candidates head-to-head as a share of all votes cast in that race, on a per-contest colour scale, since a 90-point blowout and a 3-point squeaker cannot share one ramp. Margins are two-party (R−D) as a share of the D+R vote. Third-party votes are reported but excluded from the margin denominator. District figures are built by re-aggregating 2024-vintage precinct returns onto each plan via precinct-to-district assignment, so every cycle can be measured on identical lines. The 2025 mid-decade map (PLANC2333) was enjoined in November 2025, restored by the Supreme Court in December 2025, and the injunction summarily reversed in April 2026 — it governs the November 3, 2026 election, for which no results exist yet.