Welcome to our Election Update for Wednesday, Sept. 19!

The most likely scenario in the upcoming midterm elections: split control of Congress. As of Tuesday evening, the Classic version of our model gave Republicans a 7 in 10 chance of keeping control of the Senate, slightly better than when we launched the forecast, and gave Democrats a 4 in 5 chance of flipping the House. That’s close to the highest odds for taking the House that Democrats have had since the beginning of August.

As I wrote last Wednesday, 21 U.S. House seats fit in the middle of the Venn diagram between “districts carried by Barack Obama in 2012” and “districts carried by Donald Trump in 2016.” These districts aren’t quite as fertile for Democratic gains this year as Romney-Clinton districts, but they are nonetheless a competitive batch of seats — so let’s take a closer look at the data behind our forecasts in each of them.

Nine district where Democrats are playing defense

First, nine of the 21 aren’t Democratic pick-up opportunities at all; they’re already held by a Democratic representative, so Republicans are the ones playing offense. However, as of Tuesday evening, our model gave the GOP a greater than 28 percent chance in just two of those nine: the Minnesota 1st District and Minnesota 8th District. Both are working-class districts in Greater Minnesota where the incumbents are stepping aside. Both were closely divided in 2012, but Trump won them by 15 points or more in 2016. In the 1st, an internal poll by the GOP showed Republican Jim Hagedorn with a 14-point lead, which was enough to cause our model to favor Hagedorn. In the 8th, a poll showing a slight Democratic lead balances out slightly GOP-leaning fundamentals (Republican Pete Stauber has raised more money) to produce a race that is close to 50-50.

Four districts where Republicans should hold on

Of the 12 Obama-Trump districts currently represented by a Republican, four will be particularly hard for Democrats to flip — as of Tuesday evening, our model rated them all “likely Republican.” Interestingly, all four are in New York, specifically in some of the state’s Trumpiest corners, like Long Island, Staten Island and the North Country. The 21st District is the safest for the GOP; Rep. Elise Stefanik won by more than 35 points in 2016 and hasn’t been afraid to buck her party in roll-call votes. In the 1st District, Republican Rep. Lee Zeldin has outraised Democrat Perry Gershon in contributions from individuals, $2.0 million to $855,000. In the 2nd District, GOP Rep. Peter King is an entrenched incumbent (first elected in 1992) who won by 24 points in 2016, although somewhat surprisingly, his individual contributions slightly trail his Democratic opponent’s. And finally, Republican Rep. Dan Donovan won the New York 11th District by 25 points in 2016 but, so far in 2018, has been outraised in individual contributions, $1.6 million to $1.0 million.

But there’s one important caveat to our analysis: We haven’t found a single public poll in any of the four races, so our Classic and Deluxe forecasts are based largely on the districts’ fundamentals (e.g., past election results and fundraising). Ideally, we’ll get a bunch of survey results on these races — the more polling available for a race, the more our model can rely on polls as opposed to just fundamentals.





FiveThirtyEight updates its House predictions

Five toss-up districts

Polls are much more plentiful in the five Obama-Trump districts that our model rated as a “toss-up.” We’ve collected four polls so far in the New York 19th District, and six in the New Jersey 3rd. Both average out (once house effects and other adjustments are accounted for) to a GOP lead of less than 1 percentage point. As for the fundamentals, the Democratic challengers in both districts have raised more than double the individual contributions of their Republican opponents, and both Rep. Tom MacArthur and Rep. John Faso have relatively maverick-y voting records. Yet the fundamentals favor the Democrat in New York and the Republican in New Jersey, largely because the two incumbents do not have equally strong electoral track records. MacArthur didn’t face a competitive race in the New Jersey 3rd in 2016, whereas Faso had a scare in the New York 19th.

Next up, in the Maine 2nd District, two polls (once adjusted for the pollsters’ statistical bias) give Republican Rep. Bruce Poliquin a narrow lead, while a third shows the Democrat, Jared Golden, slightly ahead. (The district’s fundamentals are virtually split between the two parties.) The other two toss-ups are the Illinois 12th District and Iowa 3rd District. In Illinois, both the polls and fundamentals point to a very close race. The 12th District is quite red (it is 13 points more Republican-leaning than the nation as a whole, according to our partisan lean metric ), but Democrat Brendan Kelly has raised more in individual contributions than GOP Rep. Mike Bost (are you sensing a pattern?). But in Iowa, the fundamentals point to a 5-point Democratic win: The 3rd District is, after all, just an R+2 district in a very Democratic-leaning environment. However, the polling suggests the opposite: that the Republican “should” win by 7 points, largely thanks to one recent outlier poll that gave Rep. David Young a 16-point lead (before our adjustments).

Three districts likely to flip to Democrats

Finally, our forecast rated three Obama-Trump districts as “likely Democratic.” The New Jersey 2nd District is an open seat being vacated by GOP Rep. Frank LoBiondo, but national Republicans pulled all support from their candidate, who has raised a relatively paltry amount of money and has some serious PR problems (see below). In the Minnesota 2nd, an internal poll gave GOP Rep. Jason Lewis a 1-point lead, but when that’s adjusted for the pollster’s statistical bias toward Republicans, it translates to a nearly 7-point lead for the Democratic challenger. Lewis also sits in a closely divided district (R+2) that he barely won in 2016, which suggests it should be Democratic-leaning in 2018’s political environment. The story is similar in the Iowa 1st District, a D+1 district where Republican Rep. Rod Blum is currently being investigated by the House Ethics Committee, which hurts him in our fundamentals calculations. And although these missteps don’t factor into our model, Republican candidates in both the New Jersey 2nd and Minnesota 2nd have also become embroiled in controversy — in their case, by circulating racist and sexist comments.