If a tree falls in the forest, and only swing voters are around to hear it, does it make a sound?
Whatever your answer is to the original philosophical question, it should remain unchanged in this version. Swing voters, like political “independents,” are rarely more than science fiction.
That is not to say that voters never change their minds. It’s that when they do so, they tend to trade one opinion for another, not graduate from being undecided (no matter what they tell pollsters). More evidence for this comes from Columbia University’s Andrew Gelman, who takes to the Washington Post’s Monkey Cage blog to explain the results of his latest political science survey, conducted along with coauthors David Rothschild, Sharad Goel, and Doug Rivers.
At the blog, Gelman quotes the study’s abstract:
How can election polls swing so much given the increasingly polarized nature of American politics, where switching one’s support between candidates is a significant move? We investigate this question by conducting a novel panel survey of 83,283 people repeatedly polled over the last 45 days of the 2012 U.S. presidential election campaign. We find that reported swings in public opinion polls are generally not due to actual shifts in vote intention, but rather are the result of temporary periods of relatively low response rates by supporters of the reportedly slumping candidate. After correcting for this bias, we show there were nearly constant levels of support for the candidates during what appeared, based on traditional polling, to be the most volatile stretches of the campaign. Our results raise the possibility that decades of large, reported swings in public opinion — including the perennial “convention bounce” — are largely artifacts of sampling bias.
The short story is much of the apparent changes in public opinion are actually changes in patterns of nonresponse: When it looked like Romney jumped in popularity, what was really happening was that disaffected Democrats were not responding to the survey while resurgent Republicans were more likely to respond.
Gelman also notes a bit of humorous backstory:
This is a big deal and it represents a major change in my thinking compared to my 1993 paper with Gary King, “Why are American Presidential election campaign polls so variable when votes are so predictable?” At that time, we gave an explanation for changes in opinion, but in retrospect, now I’m thinking that many of these apparent swings were really just differential nonresponse. Funny that we never thought of that.
That original question, though, arguably has accrued more relevance over the last two decades. It also seems like a fascinating reversal of process. Polls always carried with them a sense of scientific authority (today they are just plain fetishized). So even though the variability of polls in many elections just didn’t seem right, there wasn’t much more to that. The numbers said one thing and instincts or personal experience another. The numbers always won out. Gelman and Co. have flipped the script in a way.
The polling “swings” are consequential, however. As the authors note in their paper, they inspire a narrative of momentum and create a bandwagon effect:
For example, the Romney campaign saw a surge in donations and volunteers in the days following the debate, attributed in part to his perceived viability. Moreover, of the $400 million raised in the month between the debate and election day, donors making rational investment decisions would have likely directed some of their contributions to tighter senatorial elections if they did not believe the race for president was so close. Further, in an age of highly targeted campaign strategies (Hillygus and Shields 2009), misunderstanding voter intent likely affects decisions ranging from state-by-state spending (over $650 million was spent in that final month) to the general tone of the candidates. Finally, major poll movements often extend into the wider world, affecting, for example, stock and commodity prices (Snowberg, Wolfers and Zitzewitz 2007).
This helps explain why Barack Obama’s campaigns have been so successful. In both 2008 and 2012, the GOP presidential nominee was not exactly beloved by the party’s base. Obama had no such struggles. As I wrote here last month, we may scoff at the methods by which the Obama team fires up the Democratic base, but it is undeniable that firing up the base is an important component of a successful campaign.
In 2012 especially, it appeared bizarre that Obama had abandoned “independent” voters for Big Bird and birth control–a strategy that relied on the angry left to power the campaign. There’s a good reason to ignore independents: as I’ve argued before, they don’t exist, at least not in the numbers the media thinks. The country is deeply polarized; according to Pew, “Republicans and Democrats are further apart ideologically than at any point in recent history.” Vote swings are not the result of swing voters, and campaigns should plan accordingly.