How many House seats will the GOP gain this fall ? And which seats are likely to flip ? In general, there has been little specific discussion about this topic, other than political commentators’ giving various estimates, with little in the way of supporting data. In this article, we would like to, using publicly available data, report how we think the race for the House stands right now.

To keep the mathematics simple, the first and most important number is the partisan breakdown of the House – 256 Democrats and 179 Republicans (technically, there are a handful of vacancies, but for purposes of this analysis, we’re allocating the open seats to the party who held the seat). To gain control of the House, the GOP must pick up 39 more seats than they lose. This “net number” is crucial, because even in the 1980 and 1994 GOP landslides, four House seats were picked up by Democrats each time. Only in the 2006 Democratic landslide was there a “perfect sweep” – not a single Democratic held seat changed hands.

Since the year started, we compiled a list of (1) all Republican House seats that voted for Obama in 2008, and (2) all Democratic House seats where Obama got 65% of the vote or less (we explained the significance of the 65% figure in this post). Using this criteria, we come up with a list 200 House seats, of which 166 are controlled by the Democrats and 34 by the Republicans. With the exceptions of “Joseph” Cao of Louisiana and Charles Djou, we have not seen evidence that any incumbent Republican is in electoral trouble, and even those two lead in the polls with more than 50% of the vote. Similarly, only two open Republican House seats are vulnerable. This means that the “playing field” as we see it is really 168 House seats (166 Democrats and 2 Republicans).

We have seen polling for 37 Democratic held seats where the Democratic candidate or incumbent trails in the polls. Similarly, there are two Republican House seats (Mike Castle’s seat in Delaware and the Mark Kirk seat in Illinois) where the Democrat leads in the polls, but with less than 50% of the vote. If you included these races in the picture, Republicans would gain a net of 35 House seats, for 214 seats, or four seats shy of control.

While this 35 seat figure is in line with what most pundits are saying, there is a significant omission in their analysis – they don’t mention the fact that there are quite a few House races where no polling data has been publicly released. In other words, in 79 Democratic held seats, our theoretical criteria of which seats are “safe”, “watch list”, or “vulnerable” have no way of being verified or contradicted by actual polling. Therefore, for the remainder of our analysis, we will show you how the GOP could end up gaining anywhere from 35 to 160 House seats, for a House membership of anywhere between 214 and 339 Republicans.

As things stand today, we believe that at a minimum, the Republicans will end up with at least 214 House seats. We also know that presently there are 8 Democratic open seats that can reasonably expected to be picked up by the Republicans, but no polling has been publicly released. Similarly, there are 17 vulnerable Democrats and 3 Democrats on the “watch list” where there is no poll information. We also believe that for the two open Republican seats in Democratic leaning territory, a GOP wave can generate sufficient enthusiasm to life the GOP candidates in those districts to victory. If you add these seats to the “base” of 214 GOP seats, you will be looking at 244 GOP seats, or a pickup of 65 Republicans.

The next group of Democrats that should be viewed as possible takeover targets are those classified as “safe” because they are at or above 50% in the polls. However, it can be argued that greater GOP enthusiasm can erase 5% of their current poll standings. And it needs to be mentioned that these polls showing Democrats in good standing need to be critiqued – there is inconsistency as to whether that poll used registered or likely voters – we explored the importance of these nuances in this post. Therefore, while there are 12 Democrats classified as “safe”, their poll numbers are less than 53%, and we don’t know about the quality of the poll sample. These Democrats could find themselves on the losing end in November. If you included these Democrats in the calculations, you’d now be looking at 256 GOP seats, or a pickup of 77 Republicans.

Furthermore, you also have 32 Democrats on the “watch list” – polling performed in their races shows them in the lead, but with less than 50% of the vote. Nearly all in this list are incumbents. At this stage in the game, there is little incumbents can do to improve their standing in the eyes of the electorate, so it’s not unreasonable to assume that some or all of the Democrats in this group will lose to Republicans. So if you included these Democrats in the calculations, you’d now be looking at 288 GOP seats, or a pickup of 109 Republicans.

Finally, theoretical criteria we used (such as Obama % and 2008 re-election percentage) has caused us to classify 51 Democrats as “safe.” However, no polling has been released on these races. If we wanted to pretend that some or all of these seats will surprise us on Election Night (in fact, we already saw this happen in a poll conducted in the House race with North Carolina Democrat David Price this past week), you theoretically could have an additional 51 Republicans, for a House of 339 Republicans, or a whopping gain of 160 Republicans.

Naturally, we are not expecting (nor do we wish to give the impression that we expect) a veto proof GOP House majority of 339 House Republicans. Rather, we wish to debunk partisan spin with actual data to show “best case” and “worst case” scenarios. We have also attached a list of those House seats mentioned above.