The 2020 elections are still 16 months away and yet pollsters are out in force, giving us just enough information to break out our crystal balls and make wildly irresponsible predictions. This is the third post in a four-part series looking at the Generic Ballot and its utility as an election predictor. You can read the first post in the series here

The Generic Ballot is a poll question that aims to measure the national popular vote for the House of Representatives. Respondents are asked to choose between a nameless Republican and Democrat for Congress. Gallup asks it this way: “If the elections for Congress were being held today, which party’s candidate would you vote for in your congressional district — the Democratic Party’s candidate or the Republican Party’s candidate?”

Each party’s number of seats in the House of Representatives, however, is not determined by the national popular vote. A party that gets 45% of the popular vote will not always (or usually) receive 45% of seats in the House. Instead, we hold 435 individual elections, district by district. There are, therefore, two degrees of separation between the Generic Ballot and House seat allocation. The Generic Ballot predicts the national House popular vote which then can be used to estimate each party’s seat allocation.

How U.S. House Elections Work
The current conception of U.S. House elections — 435 individual districts with one representative each — is not mandated by the Constitution. Regarding seat apportionment among the states, the Constitution stipulates that states have House representation proportional to their population and that each state has at least one representative. As for elections, the Constitution says that only these representatives should be “chosen every second Year by the People of the several States.”

Instead, the Uniform Congressional District Act, a federal law passed in 1967, mandates the use of single member districts in all states with more than one representative except Hawaii and New Mexico.1These two states were given exceptions, allowing them to continue electing representatives at-large. Both states have since done away with this practice. Without this statute, a state could theoretically establish multi-winner elections, where all of a state’s voters choose from the same slate of candidates and the candidates with the most votes fill the number of open seats in order of votes received. If, for example, there were eight candidates running for three open statewide seats, the top three vote getters in the statewide election would fill those three seats. As of now, though, this is against federal law.

Maine did run ranked choice elections in 2018 for House and Senate, rather than traditional plurality elections. But even in this system, the state is split up into proportional districts according to population and each district gets one representative. With this caveat, the this single-member district, first past the post system of choosing representative dominates U.S. House elections. So that’s what we will focus on here.

Why Party Seat Allocation Differs From The Popular Vote
Single member districts mean that some votes will not be represented. The votes of Republicans in a heavily Democratic districts, Democrats in heavily Republican districts and third-party voters are essentially useless. And in close elections — say a candidate wins 51% to 49% — nearly half of the electorate’s votes go without representation. Unsurprisingly, on a national scale, this means party representation does not match the national popular vote.

A key concept is the ‘wasted vote’. There are two kinds of wasted votes. Type One is a vote that does not go the winner. So, in a 60-40 election, the 40% of votes that did not go to the winning candidates are Type One wasted votes. A Type Two wasted vote is any vote for the winning candidate over the threshold to win the election. It is essentially an additional vote that the candidate would have won without. In an election with a 50% winning threshold, any vote over that 50% mark is a Type Two wasted vote. One might think that, on a national level, the number of Republican and Democratic votes would balance out. There are two big reasons that this does not happen.

1) Natural Sorting
Democratic and Republican voters are not spread evenly across the country or within states. Democrats are concentrated in urban areas while Republicans are spread out over larger, more rural areas. When congressional districts are drawn, Democrats are often naturally placed into districts that are overwhelmingly Democratic due to their heavy concentration in cities and urban areas. This creates a lot of Type Two wasted votes. If an urban district is 85% Democratic, that 35% over the 50% mark are unnecessary for Democratic representation and wasted votes. On the other hand, Republicans tend to live in suburban, exurban and rural areas. They are more evenly dispersed around the country, making it rarer for a district to be overwhelmingly Republican. This distribution is more efficient for Republican voters, because if they live in more 60-40 districts than 85-15 districts, they have cast many fewer wasted votes.

2) Gerrymandering
Gerrymandering is the drawing of congressional districts to favor one party over another. Because state legislatures are responsible for drawing congressional districts, they often try to maximize their party’s federal representation.

The two methods used in gerrymandering are ‘packing’ and ‘cracking’. Both involve maximizing the opposite party’s number of wasted votes. Packing is drawing a small number of congressional districts that heavily overrepresent the opposition party’s voters, creating a lot of the Type Two wasted vote. Cracking is the opposite of packing — diffusing the opposition’s voters into districts so as to create Type I wasted votes.

Most gerrymanders are a combination of Packing and Cracking. Imagine a state that has 100 voters: 50 Republicans and 50 Democrats and five congressional seats of 20 people each. A Democratic legislature could draw the districts to look like this:

1) 20 Republicans
2) 7 Republicans + 12 Democrats
3) 7 Republicans + 12 Democrats
4) 8 Republicans + 13 Democrats
5) 8 Republicans + 13 Democrats

The Republican Packing in District 1 along with the Republican Cracking in Districts 2 – 5 allowed Democrats to win four out of five seats in a state that his half Republican.

Natural Sorting and Gerrymandering are the two biggest reasons that the national popular vote and seat allocation among the parties do not match. There are, of course, other reasons: third party votes, unequal district sizes, differing voter turnout in districts, etc. But these two are the biggest structural and geographic factors of our system that ‘distort’ House representation away from the popular vote. Now that we know what causes the gap between popular vote and House representation, we can look at how significant this gap has been in the past, how much it matters today, and which party tends to benefit from it. Next week: SEAT ALLOCATION VS THE POPULAR VOTE (PART 2)



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