In the most recent post over at 538, Nate Silver makes a brief parenthetical statement about Pennsylvania that got me wondering if there was something bigger going on.
(So pronounced are the regional variations in Pennsylvania that Republicans were able to devise a redistricting plan in which Democrats won just 5 of the 18 seats for the House of Representatives this year despite their House candidates winning more votes over all throughout the state.)
And this was also true of Ohio, where Republicans won 12 out of 16 House seats despite losing the state’s popular vote to Obama. Those are huge lopsided Congressional advantage for Republicans in a swing state, especially ones with a Democratic lean in the popular vote. And the Republicans retained the House despite losing at most other levels across the country. This leads to the question: How pronounced is the difference between each states’ Congressional representation and its votes for President? (And if the discrepancy is large, what are the reasons?)
Maybe this has been covered elsewhere, but out of curiosity I wanted to see what the picture looked like for myself. I gathered two sets of data:
1) The state-by-state current vote totals for Obama vs. Romney (from the Cook Report spreadsheet).
2) Each State’s Congressional delegation percentage, from the 113th Congress state listing on Wikipedia.
Here’s the final CSV file.
I tried two ways to visualize the data to see what the current state of the discrepancy between the Obama/Romney state voting and the Congressional delegation percentages (i.e 5 Dems and 5 Reps would be 50%).
Way #1: By Popular vote margin
A couple things stand out here:
1) Only 1 state, AZ, had Romney winning the popular vote but Democrats holding a majority of the Congressional Delegation.
2) Several states had the reverse, where Obama won the popular vote but Republicans had a majority of the delegation.
3) Almost every swing state, including OH, FL, PA, VA, NV, CO, and NC have lopsided Republican delegations (Updated: not NH).
Way #2: By Quadrant
It does seem like the entire chart, which you would expect to center at 50% population vote matching with 50% congressional representation, is shifted several steps to the right. The discrepancy between B and C does not tell the whole story, but it does seem clear that the popular vote totals have to be very far in the favor of Democrats before the House delegations start to match (except one time, in Arizona).
There are several reasons this could be the case, here are the ones I am thinking:
1) Better Republican candidates at the House level across the board.
This seem unlikely because of the sheer numbers in every state. Having all those candidates randomly be better than their opponents at once is pretty unlikely.
2) Obama more popular than other Dems in general
I don’t like this answer because Dems did so well across the country in other state-wide races, including ballot questions and Senate races.
3) The Incumbency advantage
This one seems very plausible to me. Incumbents have huge advantage (fundraising, media appearances, recognition, etc) and there was a very big Republican wave in 2010 that left a lot of Republicans as incumbents for 2012.
4) Aggressive Gerrymandering of districts
Republicans across the country, swept into power in 2010, had the unique advantage in many states to use the once-a-decade census numbers to draw up new lines and redistrict states in a partisan manner. We in MA have a nice long history of this sort of shenanigan, I think at least one speaker has gone to jail for it?
If #4 was the case, then the Republican House majority could be around for a very, very long time.
Any thoughts on how could we determine if that’s the situation. or if its just a combination of the other 3? (or is something else going on?)