Arkansas polls diverge, and our projected Cotton margin widens

Two Arkansas Senate polls are in our average, and they do not agree. A J.L. Partners survey of 803 likely voters, fielded August 14-18, put Republican Tom Cotton at 51 percent and Democrat Hallie Shoffner at 35, with 4 percent for other candidates. A 2040 Strategy Group poll of 586 likely voters, fielded July 17-25 and reported by the Arkansas Times, had Cotton at 46 and Shoffner at 43 — close enough that it does not establish a lead for either candidate.

Our model leans on the more recent and larger of the two. It now projects a mean margin of R+18.6, with a 5th-to-95th-percentile range running from R+29.0 to R+8.1. That is a slightly wider margin than the previous run, which had R+17.1 and a range of R+27.7 to R+6.4. The win probability did not move with it: our model gives Shoffner a 0 in 100 chance, and Cotton essentially 100 percent.

So the new numbers changed the expected size of the result and not the expected winner. Even the friendlier of the two polls for Shoffner, the July 2040 Strategy Group survey, sits well outside the range our model treats as competitive once it is weighed against the August data.

Nationally, the picture is closer. Our average of 28 generic-ballot polls over the past 45 days stands at D+6.5. Our Senate model puts the Democratic mean at 50.2 seats, with 51 needed for Democrats to win control and 50 enough for Republicans, because the vice president is a Republican and a 50-50 chamber breaks their way. That leaves Democratic control at 49 percent and Republican control at 50 percent. Arkansas is not among the seats that decide it in our simulations.