Sand built it. From June to August, Sand’s ads put cancer and polluted water on air: “number one in rising cancer rates”, and “deny immunity to the companies that are polluting our water”. None of Lahn’s ads before September touched either.
Lahn took it in a week. On September 16, Lahn launched “Who Pays For It?”. His ad says Sand’s biggest donor makes the nitrate fertilizer “poisoning Iowa’s rivers”. In the week to September 24, Lahn added 98% of his new dollars to that message, and “Not Once” held it at 98% the week after.
Sand went back to defend it. Sand’s share rose from 1% to 42%, then 63%. His “All Lies” ad says the company is his wife’s family’s, that it doesn’t make nitrate fertilizers and hasn’t polluted any drinking water. New ads on cancer research followed.
By October, the ground had moved again. Lahn’s new ad, “Beliefs”, is on transgender policy, deportation and the Green New Deal, and in the latest week he added almost nothing to the issue. Sand’s two biggest new buys were an ad on taxes and one in which a cancer patient says Lahn backs hospital cuts, an ad about hospitals.
What this means for a plan built now:
Who owns an issue on air can change inside a week. In this race it moved three times in four weeks. A plan that assumes September’s ground in late October is reading an old map. Read the air weekly, ad by ad.
Iowa, September and October 2026. In the week to September 24, Lahn added more than Sand to water and cancer in every market where either added much. The week after, Sand added more in the Davenport and Ottumwa markets, and the two sides were about level in Des Moines and Sioux City. In the week to October 8, Sand added more only in Sioux City, and Davenport was about level. In the latest week, Sand added more in Sioux City, Omaha and Mason City. About level means the smaller side added at least four-fifths of what the larger did. Both sides bought statewide; the colors show who added more, not where they aimed.
What this is. The Persuadable Gap is a read on the voters campaigns are actually chasing, from Causal and PharosGraph. This edition is a one-off AdScape™ showcase, built from the ads each side booked and aired. Unlike the usual editions, it has no voter data. It is a diagnostic, not a forecast. We never say who will win.
How it is built. Dollars added: the change in AdImpact’s record of each ad’s dollars between weekly snapshots, September 10 to October 15, 2026; it includes booked flights. Water and cancer: PharosGraph’s read of each ad’s script; an ad counts when it is about water quality, pollution or cancer. One Sand ad, “Iowans Pay The Price”, features a cancer patient but is about hospital cuts, so it is not counted. Counted in, Sand’s share in the week to October 15 is 48%, not 10%. A second reader, coding blind, agreed on 34 of 34 ads. Quotes are the ads’ own claims. Sides: each candidate’s campaign and the groups credited to it. Source: AdImpact, via PharosGraph AdScape