Minnesota Senate poll shows a 46-45 race as our forecast falls to 70 percent

A new InsiderAdvantage survey of 1,200 likely voters, fielded September 28-29, finds the Minnesota Senate race close. The Democrat takes 46 percent and the Republican 45 percent, with 2 percent for other candidates and 1 percent for an independent. A one-point gap is not a lead. The poll describes a race that is effectively even.

Our forecast moved on it. Our model now gives the Democrat a 70 in 100 chance of winning this open seat, which is held by Democrat Tina Smith. That is down from 92 percent in our run at 8:32 AM ET this morning, the figure this site reported yesterday. Our projected margin has narrowed from D+7.8 to D+2.9.

The range of plausible outcomes has shifted with it. Our model's 5th-to-95th percentile range now runs from R+6.4 to D+12.1, compared with R+1.4 to D+17.1 before this poll. A Republican win now sits well inside that range rather than at its edge. The Republican's chance in our model is 30 percent, up from 8 percent.

The race matters for the chamber. Our model gives Democrats a 54 percent chance of winning Senate control and Republicans 45 percent. Democrats need 51 seats for a majority. Republicans need 50, because the vice president is a Republican and a 50-50 tie goes to them. Our model's average outcome is 50.6 Democratic seats, just short of the Democratic threshold. A competitive Minnesota narrows the Democratic path.

The national environment is unchanged by this poll. Our generic ballot average stands at D+8.2 across 30 polls from the past 45 days. With 34 days until the November 3 election, the Minnesota result is one survey. Our forecast will move again as more polls arrive.