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Simulating the major House ratings

House

As if the big Swingometer update wasn’t enough, I’m not done projecting the House today. Taking a cue from Patrick Ishmael I’m going to simulate today the elections based not just the latest seat-by-seat Cook Political Report ratings, but also on those of Congressional Quarterly’s, the Swing State Project’s, and Larry Sabato’s.

Swingometer right now says R+52 from 2008. Ishmael right now also says R+52, though from right now and not from 2008. I expect these popular analysts still to be too cautious to project a big Republican win, but let’s find out.

First up we have Congressional Quarterly. the situation: 169 Safe D (0 flips), 21 Likely D (1 flip), 29 Lean D (1 flip), 36 Tossup (34 D, 2 R), 5 Lean R (1 flip), 7 Likely R (1 flip), 168 Safe R (2 flips, 2 vacancies).

I will simulate this giving safe seats a 0% chance of an upset, likely seats a 1% chance, lean seats 10%, and toss ups go 50/50.

Results after 100,000 trials: Mean and median outcome is D 235-R 200. A gain, but not a majority, for Republicans per CQ. This is to be expected when virtually no seats held by Democrats are being put on the Republican side, even a seat like SD-AL where Kristi Noem is polling very well against Stephanie Herseth-Sandlin.

Next up: Swing State Project. While CQ listed every seat, SSP follows the convention of listing only those races which are competitive or flipping. As a result, we see 29 Likely D (1 flip), 35 Lean D (1 flip), 35 Toss Up (33 D, 2 R), 6 Lean R (3 flip), 14 Likely R (2 flip).

With the same probabilities, the results after 100,000 trials: 21 seat Republican gain as mean and median, which again would not give Republicans the House of Representatives. The current House makeup is 255 D – 178 R with two vacancies, one of which was on the SSP lists from the Republicans, and the other a safe district for the Democrats. As a result, the projected makeup is 235 D – 200 R.

Third we have my standby from previous simulations: Cook Political Report. The tilt on this one is as staggering as ever: 102 seats of the Democrats are listed, versus 18 for the Republicans. 30 Likely D, 30 Lean D, 40 Toss Up, 6 Lean R, 14 Likely R.

100,000 simulations later: Finally a different result, but not much different. R+24 seat mean and mode is what I come up with, which of course translates into a 232 D – 203 R majority for the Democrats.

Last: Larry Sabato. Again, only competitive seats are listed: 24 Likely D (0 flip), 25 Lean D (3 flip), 27 Toss Up (26 D, 1 R), 17 Lean R (13 flip), 9 Likely R (0 flip). This seems to be a more aggressive ratings chart than the others. Will it give Republicans the majority, though?

After 100,000 simulations, no, the results aren’t much different. The dearth of toss ups from the other side costs the Republicans as much as the abundance of flips. R+24 seat mode, though a 23 seat mean so we’re right on the boundary between the two. We’ll call it 24 though as it’s the most likely individual outcome. That’s a 233 D – 202 R majority.

Interestingly though. Sabato also tosses out a number: R+32. I must assume that means Sabato also has in his pocket a number of races that are flipping Republican but aren’t competitive that way.

So how do the raters stack up against the Swingometer after all that effort? Here they are, sorted by net outcome:

Source R D
Ishmael 231 204
Unlikely Voter 230 205
Sabato Quote 211 224
Cook 203 232
Sabato Sim 202 233
CQ 200 235
SSP 200 235
Current* 178+1 255+1
* Vacancies listed as an added seat for the previous holder

Curious. All of the big seat-by-seat ratings can’t seem to find enough individual seats for the Democrats to lose to match the national mood captured in the generic ballots. That tells me some Democrats right now probably believe they are safe, but will lose in November.

By then these ratings are likely to have moved, but I think that both past experience and current polling suggest that these well-known ratings sources are not reliable as an early warning. Unless the generics are well off this year, the seat-by-seat ratings are going to be more of a coincident indicator than a leading indicator.

From Unlikely Voter

COMMENTS

  • mboyle1988

    Look at the RCP average though. They’re much more in line with you all.

  • IJB

    …I also gently ribbed Neil over at the Unlikely Voter that he skipped over Stu Rothenberg’s ratings as well.

    Perhaps Neil can save analyses of these two for a later post… ;)

  • http://www.hakubi.us/ Neil Stevens

    I’m about to give up on these guys and go all Swingometer all the time :)

  • Return to Revolution

    I say keep up the institutional denial.

  • IJB

    As an example of that, Rollcall still “projects” the Dems winning “219″ seats vs. just 180 for the GOP, with 36 “true Tossups”. IOW, Rollcall has it such that even if the GOP wins *all* the tossups, the Dems would still control the House 219-218.

    Ah, it is to laugh… (or not… :/ )

  • cwilson

    In a wave election, almost all of the tossups go in one direction, as well as many of the “opposite leans”. If you re-run your analysis, *assuming* a wave, you’d probably do something like 90% of the tossups go toward the R, and maybe 50% of the leans.

    I’m not saying it WILL be a wave…but if it is, it will be much uglier (for the Dems) than the big boys are currently predicting.

  • rdelbov

    Florida looks to have a record midterm turnout for a GOP primary.

    So here’s the list–Maine-South Carolina-Georgia-Florida-Alabama-Tennessee-Kentucky-Indiana-Michigan-Missouri-Arkansas-Kansas-Texas-Oklahoma-Colorado-utah-New Mexico-Arizona-Wyoming–whew

    GOP folks are voting and so far only Colorado with its new mail in ballot system did a democrat turnout record.

    Republicans care and they are turning out. I know this shows in generic ballot stuff as a surge in likely voting for us. Yet we will still be surprised on election day??

    Here’s my prediction–we win nearly all of the close and super close races. That could be who knows how many extra seats.

  • roscopico

    How much trust are we to place in the results offered by these outfits when the feeling here at the front is palpably tilted toward anti-Statist feevah?

    Which party is more energized? How many of the likely/lean/tossup statist seats are in districts without a senate race drawing drones to the polls?

    Does anybody take into account the push/pull from races higher on the ticket? What I’m asking is whether a lean dem house race is safe w/o a senate race at the top of the ticket.

    Here in the land of cheese and beer we have senatorial, as well as gubernatorial races that may motivate low-information voters to save the contemptible Steve Kagen by the skin of his fraudulent snake teeth.

  • http://www.hakubi.us/ Neil Stevens

    A special election I could, in theory, but not a primary.

  • Brian_Roastbeef

    Then I expect that at least Cook will start to shift races over in numbers that more closely match the Swingometer. He’s shown that he understands what is coming in his editorials. I think he is just waiting before he makes his moves.

    Until then, when a rating org. has Herseth-Sandlin rated as anywhere from “Toss Up” to “Likely D” when I’m consistently seeing Noem up by 9 to 11, they aren’t taking these midterms seriously. I can’t take any of their ratings seriously, either.

  • 6eorge Jetson

    Actually, a little better than +45 as it’s trading a touch above 50

    Likewise, the coin-toss/median contract on the number of Senate seats to be held by Republicans post election is 48 or 49

    Republican Senate Control (51+) is trading at ~25% likelihood