Close Trafalgar poll in South Carolina leaves our Senate forecast unchanged

A new Trafalgar Group survey of 1,087 likely voters in South Carolina, fielded September 23-25, shows a close Senate race. It has Democrat Annie Andrews at 42.3 percent and the Republican at 43.4 percent, a gap of about one point.

The poll did not move our forecast. Our model gives Andrews a 10 in 100 chance of winning, the same as in our previous run earlier today. Republican incumbent Darline Graham's chance stays at 90 percent. Our model's average margin also holds at R+7.2.

The only change is at the edge of our range. Our model's 5th-to-95th percentile outcomes now run from R+16.6 to D+2.1, compared with R+16.6 to D+2.2 in the prior run. That is a small change and does not alter the picture of the race.

The Trafalgar result is closer than our model's average margin. On its own, the poll describes a race near even. Our model weighs it against everything else it has, and the result is a forecast that still favors Graham by several points.

The seat matters to the national picture. Our model gives Democrats a 56 percent chance of winning Senate control and puts their average seat count at 50.8. Democrats need 51 seats for control. Republicans need 50, because the vice president is a Republican and a 50-50 tie goes to them.