The live Polling Index updates as new polls come in, through Election Day. It's for paid subscribers to The Intersection: subscribe, then open the Substack post for the link.
How much better are Democrats polling than in 2024? Each House and Senate poll is compared with its seat’s 2024 presidential margin and adjusted for pollster bias. Positive numbers favor Democrats.
Snapshot: polls through 4 September 2026 · 60 days before Election Day
House
Swing since 2024
+11.7 points
Average Democratic gain in the seats polled.
Swing adjusted for seat mix
+9.4 points
Estimated gain in a seat that voted like the nation. Implied national margin: D+7.9.
Senate
Swing since 2024
+10.0 points
Average Democratic gain in the seats polled.
Swing adjusted for seat mix
+8.7 points
Estimated gain in a seat that voted like the nation. Implied national margin: D+7.2.
House
Swing since 2024
+10.6 points
Average Democratic gain in the seats polled.
Swing adjusted for seat mix
+9.9 points
Estimated gain in a seat that voted like the nation. Implied national margin: D+8.4.
Senate
Swing since 2024
+9.8 points
Average Democratic gain in the seats polled.
Swing adjusted for seat mix
+8.4 points
Estimated gain in a seat that voted like the nation. Implied national margin: D+6.9.
01
One dot per poll, by final fieldwork date, with rolling averages. Hover for details.
Average swing in the seats polled.
Swing in a seat that voted like the nation. Only the lines move.
02
Democratic swing from each cycle’s presidential baseline. Diamonds are the results, weighted by polls.
The trendline toggle above applies here too, with a separate seat-mix adjustment for each cycle.
03
Senate polls finishing fieldwork in the prior 30 days, against the average of the last two midterms and the last two presidential cycles.
Each poll’s two-party margin minus the seat’s previous presidential two-party margin; positive favors Democrats. Each poll counts once, with the actual nominees. Baselines: 2016 for 2018 and 2020, 2020 for 2022 and 2024, 2024 for 2026, on 2026 district lines.
Partisan firms are corrected by how they differed from other firms polling the same race within three weeks, 2018–2024, pulled toward their group’s average. Firms with fewer than five such polls get the average. Nonpartisan polls are untouched.
Democratic House polls often show close races where nonpartisan polls show comfortable Democratic leads. So for each point a seat is bluer than Trump+10, the Democratic correction shrinks by 0.4 points. For an average firm it crosses zero near Trump+2.4 and stops changing past Harris+5.
Lines are centred three-week averages, equally weighted, with at least six polls. From there to today the line uses the trailing six weeks: full weight for a week, then tapering to zero, which blunts the effect of late-released polls.
Estimates swing in a seat that voted like the nation in 2024, from the 120-day relationship between seat partisanship and swing, applied across the whole line. The uncertainty covers this adjustment only.
Every chart on this page, updated with new House and Senate polls through Election Day. For paid subscribers to The Intersection.