Susquehanna poll of Michigan Senate race moves our forecast off a coin flip

A Susquehanna Polling & Research survey of 800 likely voters in Michigan, fielded August 11-17, puts Democrat Abdul El-Sayed at 46 percent and Republican Mike Rogers at 39 percent.

That is the only new number in the race, and it moved our forecast. Our model now gives El-Sayed a 58 in 100 chance of winning the open Michigan seat, up from 49 percent in the run completed at 12:30 PM ET on August 19. The mean margin in our simulations shifted from R+0.2 to D+1.3. Earlier today this site described the race as a coin flip on the strength of two TIPP polls; on our current numbers it is no longer one, though it remains close.

The uncertainty around that average is wide. Our 5th-to-95th percentile range runs from R+9.6 to D+12.3, which is to say our model treats outcomes from a clear Rogers win to a comfortable El-Sayed win as live. Seventy-six days out, a nine-point move in the win probability off a single survey is a reminder of how thin the polling in this race is rather than evidence that the contest has settled.

Michigan matters to the national picture, which our model still rates as close to even. We give Democrats a 49 percent chance of Senate control and Republicans 51 percent, with a mean of 50.2 Democratic seats against the 51 Democrats need; Republicans need 50, because the vice president is a Republican and a 50-50 tie goes to them. Our generic-ballot average stands at D+6.7 across 25 polls in a 45-day window. A race our model puts within about a point of a tie, in a state with one open seat, is the kind of contest that decides which of those two probabilities is right.