Straight ticket voting and the city propositions

As you know, the Chron recently wrote an editorial decrying the rise in straight ticket voting. Among other things, they said:

In two highly publicized Houston propositions on the ballot last Tuesday, nearly 56,000 voters did not register a choice on the Proposition 1 drainage fee issue and nearly 46,000 bypassed Proposition 3 on red-light cameras. Prop 1 narrowly passed and Prop 3 narrowly lost. It’s likely most of those so-called under votes were straight-ticket voters who never ventured down the lengthy ballot.

I still don’t have the data to answer the question about how many straight ticket voters did not cast a ballot in the city proposition elections, but I do have precinct data now, and can try to offer some illumination here.

The first thing to determine is in which precincts there are city of Houston votes, so the other precincts can be removed. This is an inexact science, because city boundaries do not conform to precinct boundaries. In other words, a given precinct may contain Houston voters and non-Houston voters in it. What I did, very simply, was eliminate precincts that had a large disparity between the number of votes cast and the number of votes plus undervotes for the propositions. This throws out some genuinely Houston votes, and includes some non-Houston votes, but it’s the best I can do, and it gets pretty close to the actual picture.

My method estimates that 380,830 votes were cast by Houston voters, which is a bit less than 48% of the Harris County total. The county clerk puts that number at 388,611, so I’m not too far off. I also calculate that 66.7% Houston voters cast a straight ticket vote, which is nearly identical to the 66.9% rate of straight ticket voting in the county overall. So far so good.

The undervote rate for each of the three propositions, as stated by the County Clerk, is as follows:

Prop 1 total votes = 332,757
Prop 1 undervotes = 55,838
Undervote rate = 14.37%

Prop 2 total votes = 315,076
Prop 2 undervotes = 73,522
Undervote rate = 18.92%

Prop 3 total votes = 342,819
Prop 3 undervotes = 45,779
Undervote rate = 11.78%

As discussed before, the undervote rate in the judicial elections was about 5.5%, so clearly there was a higher rate of undervoting on the city propositions. That leads to two questions. Question 1 is simply, was it likely to make a difference?

I’m going to throw out Prop 2 for the rest of this discussion, for two reasons. One, there was no campaign for or against Prop 2, and as such you should expect it to have made little impression on most voters. Two, the number of undervotes is less than the difference between the Against and For totals, meaning that if all of these undervotes were changed to For votes, it still would have failed.

For Prop 1, the For vote exceeded the Against vote by a margin of 6,123. To make up a 6,123 vote difference from 55,838 ballots, you need 30,979 of them to vote Against, which is 55.48%. I suppose that’s doable, but given the closeness of the overall vote, that seems like a bit of a stretch.

For Prop 3, it’s even more stark. Prop 3 was defeated by a 19,345 vote margin. To make that up from only 45,779 ballots, you’d need to win 71.13% of them, or 32,563 votes. I don’t think so. Maybe Prop 1 opponents have a case that straight ticket voters cost them a shot at a win, but red light camera proponents have no such argument. It’s just not plausible.

There’s another way of looking at this, which leads to Question 2: How do these undervote rates compare to undervote rates in city-only elections? There’s no such thing as a straight ticket vote in odd-number-year elections, after all. Let’s take a look at the 2009 election and see what it tells us.

First, for the eleven Constitutional amendments on the ballot, the undervote rate ranged from 10.80% (Prop 2) to 16.84% (Prop 6). That range comfortably includes the undervote rates in the city proposition elections for this year. Those amendments were voted on by the whole county, however, so let’s look at city-only races. Here are the undervote rates for all of the non-Mayoral elections in 2009:

City Controller = 15.39%

At Large #1 = 28.48%
At Large #2 = 30.66%
At Large #4 = 28.56%
At Large #5 = 25.89%

District A = 18.24%
District B = 14.94%
District C = 13.30%
District D = 15.05%
District E = 14.98%
District F = 8.64%
District G = 22.51%

I only included the contested races. With the exception of District F, every race here had an undervote rate that was higher than it was for Prop 3, and with the exception of Districts C and F, every race here had an undervote rate higher than it was for Prop 1. You can say whatever you want about this, but straight ticket voting had nothing to do with it. As such, I consider the Chron’s hand-wringing to be unfounded. Like or dislike straight ticket voting as you wish, I say it had no effect on the city propositions.

UPDATE: Fixed the math on the Prop 3 undervote calculation. Thanks to Mark C for the correction.

Related Posts:

• Precinct analysis: Undervotes in the city
• One point of perspective on the repeal petitions
• Still more about straight ticket voting