Virginia Constitutional Amendment Turnout

Methodology

This page explains how the interactive estimates the current DEM and REP split implied by Virginia early turnout.

What The Estimate Is

The estimate is a turnout composition model, not a final election forecast. It asks a narrower question: given the ballots currently reported as mailed absentee and early in-person, what partisan split would those ballots imply if they resembled the 2025 Virginia lieutenant governor electorate by voting method?

Data Used

• Current constitutional amendment turnout by precinct.
• 2025 Virginia lieutenant governor precinct results.
• County and precinct geography from the Virginia map files already used in the turnout interactive.

Method Segmentation

The model keeps mailed absentee and early in-person separate. That matters because the partisan mix of mailed ballots can differ meaningfully from the partisan mix of early in-person ballots.

Calibration

For each county, the code reads the statewide 2025 lieutenant governor precinct file and calculates separate two-party margins for mailed absentee and early in-person ballots.

The two-party Republican margin for a method is:

rep_margin = (R - D) / (R + D)

Those method-specific margins are then converted into implied Democratic and Republican shares:

DEM share = (1 - rep_margin) / 2

REP share = (1 + rep_margin) / 2

This is a two-party calibration. Third-party votes are not allocated directly into the DEM/REP split.

Precinct And County Handling

• At the precinct level, the model uses that precinct’s own 2025 mailed absentee and early voting margins when available.
• If a precinct-level method split is unavailable, the model falls back to the county-level method split.
• At the county level, county totals are built from county-calibrated method splits and then summed statewide.

Vote Estimate Formula

For each geography, the estimated vote split is:

DEM = mail_in_26 × DEM_share_mail + on_machine_26 × DEM_share_early

REP = mail_in_26 × REP_share_mail + on_machine_26 × REP_share_early

The displayed Estimated EV Turnout value is then:

(REP - DEM) / (REP + DEM)

On the map, negative margins indicate a more Democratic early electorate; positive margins indicate a more Republican early electorate.

Interpretation

• This is an estimate of the partisan composition of ballots already cast, not a claim about how every voter will answer the amendment itself.
• The model should be read as a partisan turnout-composition estimate, not a direct ballot measure tabulation.
• Because the calculation is method-specific, changes in the mix of mail versus early in-person voting can move the estimate even if raw turnout is flat.
• Because the calculation is based on historical lieutenant governor vote behavior, it should be read as a heuristic rather than a certified result or a full election-night forecast.

In short: the interactive starts with current raw turnout, calibrates mail and early in-person ballots separately using the 2025 lieutenant governor electorate, and then converts those method-level partisan splits into an estimated DEM versus REP composition for the amendment turnout.