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 26, 2008

Obama’s SC win did not need a large black turnout

Filed under: obama, race, south carolina — Brian @ 9:18 pm

Obama would have won South Carolina even if only 18% of the voters were black.

SC Dem Primary (2008) by hypotheical % African American Turnout

I used these pieces of data of estimate the candidates’ results had the African American turnout been much lower:

With 99% reporting:

  • Obama had 55% (295,091)
  • Clinton had 27% (141,128)
  • Edwards had 18% (93,552)

And Exit Poll Data:

  • 55% of Democrat primary voters were African American
    • breakdown: Obama:78%, Clinton:19%, Edwards:2%
  • 45% were white or other
    • breakdown: Obama:24%, Clinton:36%, Edwards:40%

This leads to an estimate of 529,771 total voters (for the top 3), of which 291,374 were cast by African Americans and 238,397 were cast by whites (and others).

If we assume the total number of white voters is constant and reduce the black turnout (but keeping the same candidate distribution), then we can estimate what the results would have been had the black voter turnout been much lower.

In fact, the turnout could have been as low as 18%, and Obama would have still won!

It would be sad to see the Clintons or media spin or suggest Obama’s good showing in South Carolina as solely due to the very strong African American turnout or the unique demographics in SC. Even in states with an average number of African Americans (and the same candidate breakdown*), Obama would still have won. Given that a vast majority of African Americans vote for democrats, and about half the US voters are democrats, and overall about 12% of the population is African American, then 18%-20% is a decent estimate for the total fraction of Democrats voting in a democrat primary.

*(Note: this assumption that there will be the same candidate breakdown in future states is of course not true, since Edwards’ support will not likely get any better than it was in his home state of South Carolina.  The big question is: does Edwards take away votes from Clinton or Obama?)

Interestingly, Clinton was the most race-neutral candidate. She had steady support (20% of black voters and 36% of white voters), while Edwards had very strong white support (40% of white voters) and almost no black support (2% of black voters). Thus, if the black turnout was only 18%, then it would have been a virtual dead heat with all candidates getting about 33% (but Obama getting slightly more). Also, Clinton would not have won at any of the black-turnout levels.

In the 2004 Democrat Primaries in South Carolina, 47% of the voters were black, and in this primary, 55% of the voters were black. So, even with average black turnout in South Carolina, the vote would have still favored Obama by a very large margin.

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