Redistricting Blues: GOP holds 27 seat structural edge in assembly

Thanks to Zach and Blogging Blue for the opportunity to guest blog. I’ll be discussing election analytics with a focus on Wisconsin politics.

As Blogging Blue readers know, in January Republicans will once again enjoy full control of Wisconsin state government, having retaken the State Senate earlier this month. The GOP will hold a 17-15 edge in the senate, likely to become 18-15 following the special election for District 33. In the Assembly, Republicans have a whopping 21 seat edge after having won 60 of the 99 assembly seats.

Why did Democratic assembly candidates fare so poorly when on the same night Wisconsin voters gave solid wins to President Obama and Tammy Baldwin? Obama won 53% of the vote and Tammy beat Tommy by five, but Democrats won less than 40% of the Assembly. What accounts for these contradictory messages from the voters?

For now I’ll put aside issues of incumbency, fundraising, the ADCC, recruitment, campaigns, and so forth. Instead I focus on what we can glean from raw vote counts. Every assembly district in the state was up for election, so there were no differences between the electorates in the national and state races. We will be in a better position to understand the effects of undervote or ticket splitting patterns after the GAB posts ward-by-ward results, but there is reason to believe that redistricting was the overriding factor, with voter behavior playing a much smaller role, if any.

The graph below shows predictions of the partisan breakdown of the Assembly as a function of the Democratic percentage of the statewide two-party vote. I compute these estimates using assembly district Partisan Vote Index (adPVI) values computed from results of the June 5th recall election for Governor. The adPVI is an extension of Cook’s PVI of US congressional districts to the state level. We can use the adPVI to estimate the percentage of the statewide vote Democrats need to win a given assembly district. In Republican leaning districts we add the adPVI to 50% and in Democratic leaning districts we subtract it from 50%. For example, the adPVI predicts Dems would need 53.4% statewide to win AD 50 (R+3.4) and 44.5% to win AD 55 (D+5.5).

There’s a lot to say about this chart and adPVI. For now, I’ll point out three key conclusions:

  1. the 39 seats won by Democrats is in line with the adPVI estimates. Obama’s 53.4% and Baldwin’s 52.8% of the two party vote yield estimates of 42 and 40 Democratic seats respectively. This points to redistricting as the dominant factor of the Democratic loss.
  2. Republicans hold a massive 27 seat structural advantage because of redistricting. This means that in a dead even 50/50 statewide election (point A) the GOP would hold a 63-36 seat advantage in the Assembly. To put this bias in perspective, one analysis of the new maps for US congress, which is widely through to be significantly gerrymandered, gives the GOP an edge of just 13 seats in the 435 seat House or Representatives. So, the assembly district boundaries give WI Republicans more than nine times the structural advantage as afforded congressional Republicans.
  3. The tipping point for control of the chamber is 55.5% Dem, 44.5% GOP (point B). That means Democrats would need to win by 11 points statewide to have an even chance of winning control of the state Assembly.

There’s much, much more to explore here. I look forward to doing so in the days and weeks ahead.


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19 thoughts on “Redistricting Blues: GOP holds 27 seat structural edge in assembly

  1. Joe, thanks so much.

    Justice Patrice Roggensack is up for re-election to the state Supreme Court on 2 April 2013. If we can unseat her, is there a chance for state legal challenges to the redistricting?

    1. That’s a great question John. But, I’ll have to defer to the lawyers. I do not know if there is a viable legal challenge. Regardless, Wisconsin need to get serious about redistricting reform. Neither party should be able to cement their power for ten years by creative redistricting.

      1. The last redistricting was in the legislature. In my own view, it is federally unconstitutional, but a viable case needs to be brought and litigated. A state case may also prevail but not with the current politicized and biased state Supreme Court.

    1. I’m sure there was some of that. But we have to wait until the GAB certifies to learn more about undervoting / ticket splitting tendencies. However, my analysis points to redistricting as the primary driver in the state / national disparity.

      1. I don’t think we should underestimate the partisan bias of getting rid of straight ticket voting, one of many shenanigans pulled by the GOP in the last legislative session to cement their majority.

  2. Yes. The districts were drawn to favor the GOP. Yes, with two exceptions the new lines held up in court. You bet your sweet bippie that if Dems had the felt-pen advantage a couple of years ago, you’d be dancing in the streets.

    One really popular American once said, “Elections have consequences.” Yep. They do. Your challenge in now to influence where you can, not complain about what you can not change.

    That’s the WI argument. The same thing is much reversed on the national level for those of us in the Republican camp – with one exception. Districts were also reconfigured to maintain a GOP advantage for the House of Representatives for a while.

    Nationally, we are configured to experience a divided government for at least another decade. Instead of weeping and wailing and gnashing our teeth, could we figure out what might rise to the top as good legislation and work for the smallest of common goals?

    In WI it’s a swift move to the right, though. You’ll have to keep relying upon the courts and federal takeover of state’s rights to get your way there.

    Oh, and I have absolutely no problem holding Gov. Walker’s feet to the abacus with that 250,000 job promise. Silliest thing the man’s promised yet.

  3. I fear we will not have a chance of a more balanced state legislature until the census is redone in 2020, followed by another round of redistricting. Our only hope to elect a Democratic governor to assure some check and balance.

  4. The recall election was probably a bad choice to use as a basis for this comparison. It was atypical in a number of respects. The Assembly elections will never take place in June, for example. It would be pretty painstaking work to calculate the 2010 results under the new maps, but it would make for a more accurate comparison. You should also probably average them across several cycles.

    1. Good points Greg. I used the recall election because it is the most recent statewide election and it was held with the new district lines. As you mention using elections that took place with different ward boundaries presents a variety of problems. My suspicion, however, is that other than wards near college campuses, the shape of the recall electorate was similar to November electorates for Governor and President. The good news is that we’ll soon have the results from the presidential and US Senate races to compare to.

  5. I can say unequivocally that if the dems had the power they would have never ever signed secrecy agreements and redistricted so unethically.

    Lets also be clear here, when you say

    “Yes, with two exceptions the new lines held up in court.”

    yes they held up in court because the court was unable by law to do anything about it. The court made it abundantly clear that the way they did it was unethical and dishonest and even fined the republicans lawyers for being so blatantly dishonest and unethical.

    We have a center left state, and a far right state government who has no plans whatesoever to listen to or include the democratic politicians in any decision. Which means a majority of people in WI are going to be disenfranchised by their government.

    It is disgusting yet not the least bit surprising.

    finally YOU might hold Walker’s feet to the fire for his jobs promise but you will be the only one and im guessing he will have your support and vote regardless.

    1. Nonpartisan redistricting done by the GAB was actually in Barrett’s platform in 2010. It didn’t get much play then, and people have mostly forgotten about it now.

  6. very well done and very detailed report. i always like to kick back and analyze a race/races win or lose. and while i agree redistricting hurt us badly, the issue itself will not help us in 2014. in fact to dwell on it could seriously hurt. and this is something we can’t control. there are several other areas we can control but it’s lengthy so i am emailng BB with my full reply to the “what happened” blog. i was heavily involved in several senate and assembly races, and you learn very quickly what works/doesn’t work. so for now those thoughts and a few corrections. there are 33 not 32 senate seats in WI. all 99 assembly districts were not up for reelection, only half. then the next cycle is 2014 and the other 50 seats are up. thank you all, nice blog, and i hope my letter forthcoming you will find useful. kev

    1. “all 99 assembly districts were not up for reelection, only half. then the next cycle is 2014 and the other 50 seats are up.”

      I thought Assembly seats were two year terms and Senate four year, thus it’s the Senate where about half are up for re-election in 2014, but given there are only 33 Senate districts, it is either 16 or 17 set for election.

      Correct me if I’m wrong. I did look to confirm my idea, but only in a couple of places.

  7. Every two years all 99 WI Assembly seats are up for grabs. WI State Senators serve four year terms, with half the seats (even districts) occurring during presidential election years (2012, 2016, ….) and the other half (odd districts) during the off years (2010 Governor’s race, 2014, etc…).

    Understanding the issue of redistricting is essential in order for the Dems to take back either state house.

  8. My apologies, to correct my first comment, Mr Bockhorst is correct, senate elections are even/odd not the assembly (as I stated). The entire 99 seat body is up every two years not 50/50 as i wrote. Does anyone else find it strange that the 33 member senate are 4 year terms and the house is 2 years? And the senate and assembly saleries are the same, but the senate incumbants get 16,000 for offices in their districts, assembly gets (i think) 6,000? Curious. Again ty for your patience, and sorry for any confusion (incuding myself). And ty for the great stats report. Dirty tricks like intentional redistricting are important.

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