Election Stats

January 30, 2008

How will Edwards’ supporters vote?

Filed under: edwards, florida, new hampshire, obama, south carolina — Brian @ 11:07 pm

I’ve assumed that Edwards and Obama seem to be drawing from the same pool of voters, and that he has been drawing votes away from Obama. But, maybe Edwards and Clinton are both fighting over the traditional Dems and Obama is getting a lot of Independent support? Or, in South Carolina, even though though Obama had a great day, one observation from the exit polling was that if you only looked at white voters, then Edwards would have won, with an estimated 40% of the white vote (Clinton got ~36% and Obama got ~24%). So, maybe Edwards’ voters are uncomfortable voting for Obama? Will they all vote for Hillary?

Well, we can take a look at Exit Polls to get some clues. Unfortunately, they never ask: “If you didn’t vote for your #1 candidate, whom would you vote for?” However, in New Hampshire, South Carolina and Florida, there are some tangential questions in the exit polls which relate to how they feel about the other candidates.

But, it is actually kind of hard to read the exit poll results. You have to know which rows and columns add up to 100% (or close) and which ones are a breakdown of the other. For example, here is one table from the South Carolina exit poll (which combines two questions), asking about the gender and race of the voter:

  % Total Clinton Edwards Kucinich Obama
Black male 20 17 3 0 80
Black female 35 20 2 0 78
White male 19 29 44 0 27
White female 27 42 35 0 22

The proper way convert that data table into a sentence or paragraph format is like this: Of the voters in the SC primary, 20% were black males, 35% were black females, 19% were white males and 27% were white females. Of the white males (for example), 44% voted for Edwards, 29% voted for Clinton and 27% voted for Obama; on the other hand, of the white females, 42% voted for Clinton and only 35% and 22% voted for Edwards and Obama, respectively.

Easy, right? The rows (excluding the first column) each add up to 100%. That is why we can write the sentences we wrote above: each row is a breakdown of that particular category.

However, sometime we don’t want to phrase our explanation the same way that we did above. Sometime we want to know which answers were chosen by supporters of a particular candidate. But, none of the candidate columns add up to anything useful! To demonstrate this issue, it is useful to look at a table where the rows (answers) are not evenly distributed.

Here is another exit poll question from SC: “Do you think this country is ready to elect a black president?”

  % Total Clinton Edwards Kucinich Obama
Ready 77 21 16 0 63
Not ready 22 48 29 0 23

So, 77% of voters think the country is ready to elect a black president and 22% of voters think we’re not ready. Looking at the table, you might also try to incorrectly conclude that more of Edwards’ voters think the country is not ready (29 is higher than 16, right?). Wrong. Since only 22% of voters think we are not ready, and 29% of people choosing that answer voted for Edwards, then 29% of 22% of Edwards’ voters think that we are not ready. Calculating 29% of 22% means only about 6% of all the voters. And, we know from the overall results that 18% of all the voters chose Edwards, so that means that MOST of the Edwards voters actually think we ARE ready for a Black President.

To try and make these exit poll tables more intuitive, I like to convert them to a different format. Imagine that there are exactly 100 voters, and that each number in the table shows the total number of voters with that particular candidate and answer combination (to convert the table, just multiply the percentage in the candidate column by the percentage of people choosing a particular answer). So, after you convert the normal exit poll table to a 100-person (or 100%) table, it ends up like this:

  Clinton Edwards Kucinich Obama
USA Ready for a Black President 16 12 0 49
USA Not ready for a Black President 11 6 0 5

Now this can be understood fairly easily. The 100 voters (or 100%) is distributed among all the boxes in the table. The rows add up to the total percentage choosing that answer in the poll and the columns add up to the total percentage that each candidate received. This table would be read as follows: Of all the voters in the primary, 12% voted for Edwards and also thought the US is ready for a Black President, and 6% of all voters chose Edwards but thought the US is NOT ready for a Black President (or 2/3 of the Edwards voters thought we are ready for a Black President).

(There is another way to convert these tables, which is to have each COLUMN add up to 100%, but then the rows are hard to interpret. I like this format shown here, because you can intuitively understand the rows or the columns – even though you might have to do some extra calculations in your head to get some summary percentages.)

Here are some other exit poll results, from other states and shown in the 100-person converted format which relate to how the voters feel about Clinton and Obama:

Do you think this country is ready to elect a woman president?

  Clinton Edwards Kucinich Obama
Ready 25 13 0 38
Not ready 2 6 0 15

Summary from South Carolina: A large majority (more than 2/3) of both Edwards and Obama voters think that the country is ready for a woman president. And, a majority of Edwards and Clinton voters also think the US is ready for a Black President (see above).

Do you think this country is ready to elect a black president?

  Clinton Edwards Kucinich Obama
Ready 32 9 1 30
Not ready 16 6 0 3

Do you think this country is ready to elect a female president?

  Clinton Edwards Kucinich Obama
Ready 46 8 0 26
Not ready 2 6 0 7

No matter how you voted today, how would you feel if Hillary Clinton wins the nomination:

  Clinton Edwards Kucinich Obama
Satisfied 48.8 6.4 0.8 24.0
Dissatisfied 0.6 7.6 0.2 9.8

No matter how you voted today, how would you feel if Barack Obama wins the nomination:

  Clinton Edwards Kucinich Obama
Satisfied 29.4 7.0 0.7 32.9
Dissatisfied 18.9 7.5 0.3 0.9

Summary of Florida: Edwards voters in Florida are not as willing to believe that the US is ready for a black or woman President as they were in SC, and those voters are equally split between their satisfaction and dissatisfaction over how they would feel if Clinton or Obama wins the nomination.


Is your opinion of Hillary Clinton:

  Biden Clinton Dodd Edwards Gravel Kucinich Obama Richardson
Favorable 0.0 37.7 0.0 11.1 0.0 0.7 19.2 3.0
Unfavorable 0.3 0.3 0.0 6.5 0.0 0.5 16.0 1.5

Is your opinion of Barack Obama:

  Biden Clinton Dodd Edwards Gravel Kucinich Obama Richardson
Favorable 0.0 26.0 0.0 15.1 0.0 1.7 35.3 4.2
Unfavorable 0.3 11.4 0.0 2.4 0.0 0.3 0.2 0.6

Summary of New Hampshire: 11% of NH voters voted for Edwards and have a favorable opinion of Hillary, while 6.5% voted for Edwards and have an unfavorable opinion of her (i.e. 37% of Edwards voters have an unfavorable opinion of Clinton). On the other hand, only 14% of Edwards voters have an unfavorable opinion of Obama.

All these converted questions in a Google Spreadsheet

Overall conclusion? I think that Edwards’ supporters are somewhat evenly split between Clinton and Obama, but I think Obama will gain slightly more from Edwards dropping out of the race than Clinton will – mainly due to the slightly higher unfavorable view shown by the New Hampshire voters.


January 29, 2008

Florida Primary – preparing to follow results

Filed under: florida — Brian @ 10:51 am

Wow! The Florida SOS has set up a really great website to report the results for today’s primary. Interestingly, of their 67 counties, 14 use touch-screen voting machines. Also, in addition to absentee and polling place voting, they have early-voting where you can go to a nearby govt office and cast your vote up to 2 weeks before today.

They even have a way to just download the data in a tab-delimited file (see link on left hand side of their page)! Luckily, they don’t care if you fill out the form with a GET or POST, so here is a direct link (you can use wget, too):


County election offices.

I made a script to calculate the predicted totals, based on differing voting patterns in different counties.

One thing I always like to do here at home in Washington State is get the early returns and use the differences in county voting patterns to extrapolate the totals for the whole state (based on estimates of turnout). This is usually interesting in WA because we have a large chunk of people who vote absentee, but the law here only requires the ballots to be MAILED by election day, so we end up waiting a few days to see how the election ends up. In a close race with lots of absentees, we have a lot of elections dragging out for days.

In Florida, there are also a lot of absentee ballots, but they are required to have them ARRIVE by election day (I think). So, perhaps the first reports on the Florida website will have all the absentees in one batch. This makes it easier to see if there are differences in voting patterns between the absentees and the poll voters.

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