A lopsided UT-1 poll moves our forecast, but Owen remains a clear favorite

A Lighthouse Research survey of 515 registered voters in Utah's 1st District, fielded August 31 to September 10 and sponsored by the Utah Debate Commission, found Democrat Ben McAdams at 62.7% and Republican Riley Owen at 21.2%. Other candidates drew 3.3%. The remaining 12.8% is not assigned to any option in the reported results.

Our model still favors Owen. It gives McAdams a 6 in 100 chance of winning the seat and Owen 94%. In the run an hour earlier, McAdams's chance was 1% and Owen's was 99%. Our projected margin moved from R+20.2 to R+13.4.

The survey sits far from our estimate of the race. Our model's 5th-to-95th percentile range now runs from R+27.6 to D+0.8. The poll's 41.5-point McAdams margin falls well outside that range. The range shifted toward the Democrat, from R+34.3 to R+6.1 previously, but our model treats one survey as one input. It does not take it at face value. It is the only poll of this race we have.

Nationally, our model gives Democrats a 98% chance of winning a House majority, with an average of 245.5 seats against the 218 needed. Our simulation correlates error nationally, by census division, by state and within each district. It does not link demographically similar districts in different places, because we lack the data to do so. That makes the House figure somewhat firmer than it would otherwise be. Our generic ballot average stands at D+8.2 across 30 polls from the past 45 days.