Two TIPP polls in Michigan move our Senate forecast to a coin flip

Two new surveys of the Michigan Senate race, both from TIPP Insights and both fielded August 6-10, put Democrat Abdul El-Sayed slightly ahead of Republican Mike Rogers. Among 1,528 registered voters, El-Sayed took 43 percent to Rogers' 39 percent. Among 1,215 likely voters, the split was 45 percent to 42 percent. Neither poll reports a margin of error in what we have, and both gaps are small enough that the race reads as close rather than as a lead.

Our model now gives El-Sayed a 49 in 100 chance of winning the seat, against 51 percent for Rogers, with a mean margin of R+0.2. That is a shift from our previous run, completed on August 18 at 10:30 p.m. ET, which had the Democrat at 42 percent and a mean margin of R+1.3. The new numbers narrowed the race in our average rather than reordering it: the seat was already rated near even, and it is nearer even now.

The uncertainty around that central estimate remains wide. Our simulations put the 5th-to-95th percentile range at R+11.3 to D+11.0, which is to say Michigan could plausibly finish in double digits for either party. Gary Peters, the Democrat who holds the seat, is not on the ballot; both candidates are non-incumbents.

Michigan matters to the national picture because the Senate is close in our forecast. We give Democrats a 47 percent chance of winning Senate control and Republicans 53 percent, with a mean of 50.2 Democratic seats. Democrats need 51 seats for control and Republicans need 50, because the vice president is a Republican and a 50-50 tie goes to the Republicans. Our generic-ballot average stands at D+6.7 across 25 polls in the last 45 days, a national environment that has not yet translated into a Democratic edge in our Michigan numbers.