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By Jay Cost

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Electoral Polarization Continues Under Obama

In 2000, George W. Bush campaigned as a "uniter, not a divider." It didn't pan out that way. In four years time, the electorate was evenly divided, with about half the country favoring his reelection and the other half opposing it.

This year, President-elect Obama campaigned on moving the country past its political divisions to focus on what unites it. The results from this month's election suggest he might have his work cut out for himself on this front. While his popular vote and Electoral College victories were decisive, there are indications that the electoral polarization we have seen in the Bush years persists.

To begin, we need a way to measure polarization, which is simply the accentuation of differences. So, the greater the differences among factions in the electorate, the more polarized we can say the whole electorate was. We'll put forth two ways to measure this concept.

First, we'll take an unweighted average of Obama's share of the vote from every state plus D.C. We'll use this as a baseline to calculate the standard deviation, which is a measure of the variation around the average. That's what we're really interested in. The greater the standard deviation, the more the states varied around the average, the more accentuated were their differences, and so the more polarization there was.

We replicate this method for every presidential election going back to 1948, which enables us to compare this cycle to the last fifteen:


First, notice how the graph confirms widely-held beliefs about polarization. We see that it was higher in the 1960s than the '50s or '70s. Note 1964 in particular. While Lyndon Johnson won a large nationwide victory, the South swung heavily against him. He won 61.1% of the national popular vote, but just 12.9% in Mississippi. This is polarization.1

Second, notice that it was up in 2000 and 2004. Between Nixon's reelection and Clinton's reelection, polarization was as low as it ever was in the 20th century. However, it jumped up in 2000, and remained steady in 2004. Again, this squares with common knowledge of the last eight years - which holds that there has been more polarization recently. Now, turn to the final point on the chart, 2008. Polarization was about the same this year as in 2000 or 2004. In fact, by this metric, it actually ticked up a little bit.2

This metric uses an unweighted average of a victorious candidate's share of the vote in all states as a first step in calculating polarization. This means that, regardless of population, each state plus D.C. counts for 1/51 of the victor's average. So, it might be helpful for our second metric to use the nationwide popular vote as a first step.3

We'll do that by taking the victor's share of the nationwide vote, and then by counting the number of states where his share of the statewide vote was at least ten points higher or ten points lower than his nationwide vote. This can tell us how many "polarized" states there were that year. Again, we'll replicate this method going back to 1948, and graph the results:

Polarized States.jpg

While there are some minor differences, this chart generally squares with the previous one. We again find polarization peaking in the 1960s - by this measure 1968, not 1964, was the peak year. From the 70s through the 90s, it again settled down, only to rise again with George W. Bush. Once again, we see it go a little higher with Barack Obama.4

Let's push this analysis forward by examining which states have been polarized. We'll use our second metric for this. Instead of counting the states, we'll color code maps. The following picture does this for all elections going back to 1976. States shaded blue are pro-Democratic "polarized" states. Those shaded red are pro-Republican.5


Typically, strong Republican states can be found in the Mountain Region. Utah is consistently red. Idaho and Wyoming are frequently so. We also see states in the West North Central region tilt red with some frequency: Kansas, Nebraska, and the Dakotas. George W. Bush's elections were especially polarizing because he swung all of these states into his column, rather than just a few. Meanwhile, four states in the northeast swung strongly against him: Massachusetts, New York, Rhode Island, and Vermont.

Many of these states again showed a high degree of polarization in 2008. This time, however, they were joined by most of the remaining states in the South Central regions: Arkansas, Kentucky, Louisiana, Mississippi, and Tennessee. Never before have we seen these states vote so heavily against a victorious Democrat. Ditto West Virginia, which went for Michael Dukakis in 1988.

So, by both metrics, we find that polarization did not decline this cycle. It was about where it was in the 2000 and 2004 cycles, a point that's higher than anything we have seen in the last 30 years.

Before we discuss the implications of this, there are some important caveats to note. To start, any argument about a concept like polarization is only as good as the empirical metrics for it. We have two metrics that are pretty good, but any limitations they have will inevitably limit the conclusions we can draw. For instance, these are not metrics for ideological polarization - so we're not discussing that concept here.

Another caveat. We have operationalized the concept of polarization such that we're measuring divergence around some central number, be it the average vote across all 50 states or the national vote. However, we have not yet taken into account the central number itself. It's pretty important. By these metrics, polarization was about where it was in 2000. However, Bush won 47.9% of the vote in 2000 to Obama's 52.7% in 2008. That puts President-elect Obama in a stronger position than his predecessor. President Bush won a polarized election in 2000 with less than half the vote. President-elect Obama won more than half. That makes a big difference.

With these caveats down, what conclusions can we draw from this analysis? First, it is fair to say that this indicates that the political polarization we have seen in recent cycles cannot solely be chalked up to the personality of George W. Bush. Instead, it appears as though there might be a systemic cause, one that accounts for the elections of 2000, 2004, and 2008 displaying polarization regardless of who is on the ballot.

There's a second conclusion to draw. Pundits have been giving a lot of free advice to the President-elect, drawing heavily upon the experiences of exceptional presidents from years gone by. FDR and Lincoln seem to be the most widely referenced. If I were to suggest a previous Chief Executive the new President-elect should study closely, I'd recommend George W. Bush.

The essential job of the President is to be the leader of all the people. He is the only official we all select; accordingly, he's the only one who can claim to represent all of us. That poses a special challenge when the people are polarized, and this has been a problem for the 43rd President. Regardless of one's opinion of George W. Bush, it is fair to say that he has not governed with an eye to those who have strongly opposed him.

When you consider Article II of the Constitution against what past Chief Executives have actually done, it becomes clear that the President's greatest powers are informal, not written down. In many respects, the President does what the people allow him to do. Accordingly, if he begins his tenure with a faction that is disinclined to him, and proceeds to antagonize it - his power can be diminished. That faction can rise in opposition to thwart him, which is easy to do in our system of "checks and balances" that intentionally protects minority rights. I think something like this has happened to Bush over the last few years. What was perhaps a mere disinclination to him in 2000 became much more salient in the subsequent years. This opposition had eroded his informal power by 2005, put the Democrats in control of Congress by 2006, and delivered Obama a sweeping victory by 2008.

Given the data presented here, I think this is a cautionary tale for the President-elect. This does not mean, of course, that he must govern like a Republican from Kentucky. Far from it! It just means he should be aware that there are factions in the country that strongly opposed him, and he should be careful with how he manages these groups. He does not have to do what they want him to do, but he should not overly antagonize them.

The political consequences of that could be harmful. For instance, in the states shaded red in the 2008 picture, there are about 20 white Democratic Representatives and 7 Senators who will stand for reelection at least once in the next eight years. President-elect Obama has to be mindful of them - otherwise, they could go the the way that the New England Republicans have gone in the Bush years.


[1] Prior to 1948, polarization was much higher by either metric. The reason is that the South was a one-party region, voting overwhelmingly Democratic in most every cycle. Occasionally, Republicans who won large nationwide majorities could snag a few Southern states. However, by and large, Republicans ran into the same trouble that Teddy Roosevelt faced in 1904. TR won 56% of the nationwide popular vote that year, but pulled in less than 5% in South Carolina. Conversely, FDR won about the same share of the nationwide popular vote in his four victories while winning 85%-99% of the vote in South Carolina.

[2] The value for 1964 needs to have a metaphorical asterisk placed next to it because Lyndon Johnson was not on the ballot in Alabama. The standard deviation for that cycle is calculated by taking no value for the state. If he had been on the ballot, he probably would not have done much better than he did in Mississippi, which typically votes in tandem with Alabama. The same goes for 1948 when Harry Truman did not appear on the ballot in Alabama. Including Alabama would increase the standard deviation for both years.

[3] I also calculated weighted standard deviations (where each state is factored according to its share of the nationwide popular vote) and tracked them over time. The results were quite similar to the unweighted standard deviations:

Weighted Polarization.jpg

Again, we see polarization drop in the 70s, 80s, and 90s - only to make a comeback with the elections of George W. Bush and now Barack Obama.

We also see that, overall, polarization is lower by this metric - even though the ratios from year to year are about what they were using the unweighted metric. The reason for this is that a lot of sparsely populated states - Alaska, the Dakotas, D.C., Wyoming, etc. - tend to exhibit polarized behavior in most cycles. In our unweighted average, each of these places counts for 1.9% of the total. Now that we're weighing each state for population - they count for less, typically between 0.2% and 0.3%. This has the effect of pushing the metric down across all years. Of course, because these places always tend to vote the same way cycle after cycle, weighing them does not alter the ratio between cycles, which is what we are really interested in.

[4] We can tweak our cutoff point, maybe make it +/- 8 points or 12 points, instead of 10 points. That would change the number of polarized states in each cycle, but the crucial point is the same: the last few cycles have seen polarization go up, and in the most recent cycle it is as high as it has been in many decades.

[5] The picture doesn't capture it, but Washington D.C. would be shaded blue in every election. Alaska would be shaded red in most of them, and Hawaii in many of them. This should condition how we interpret the previous graph. Alaska first voted in a presidential contest in 1960. The District of Columbia voted for the first time in 1964. Since polarization is typical in both places, that essentially inflates the number of polarized states from 1960 to the present by at least one and sometimes three units.

-Jay Cost