Princeton Election Consortium

A first draft of electoral history. Since 2004

Brief update

August 30th, 2014, 7:33am by Sam Wang

Thanks for your feedback. The comment thread from the previous post clarified my thinking. Drew Linzer dropped in! Also, welcome to Rachel Maddow viewers.

The banner at the top of the page gives the poll-based “snapshot probability” for who would end up controlling the Senate based on an election held today. Based on PEC’s track record since 2004, this will move toward the final outcome in the coming weeks.

Long-term forecasting is based on methods that worked nearly perfectly in 2010-2012. We will soon install code to display the long-term forecast, which is also based purely on polls. Currently, the long-term forecast for Democratic control on Election Day is 65%, about 2-1 odds in favor.

→ 34 CommentsTags: 2014 Election · Senate

Senate Democrats are outperforming expectations

August 28th, 2014, 9:42am by Sam Wang

[Note: this  is a work in progress. I'm basically seeking comment as I develop a November predictive model. Please give your feedback... -Sam]

I’ve been asked why the PEC Senate poll snapshot is more favorable to Democrats than forecasts you’ll find elsewhere: NYT’s The Upshot, Washington Post’s The Monkey Cage, ESPN’s FiveThirtyEight, and Daily Kos. All of these organizations show a higher probability of a Republican takeover than today’s PEC snapshot, which favors the Democrats with a 70% probability.

Today I will show that in most cases, added assumptions (i.e. special sauce) have led the media organizations to different win probabilities – which I currently believe are wrong. I’ll then outline the subtle but important implications for a November prediction. [Read more →]

→ 76 CommentsTags: 2014 Election · Senate

Could a Kansas independent shift control of the Senate?

August 27th, 2014, 2:36pm by Sam Wang

Normally, both Kansas Senate seats are deep red: one’s been Republican since Franklin Roosevelt was President, and the other one dates back to Woodrow Wilson. So it’s not surprising that even though incumbent Senator Pat Roberts has an abysmal 27% job approval rating, polls indicate that he would still beat his Democratic opponent, Chad Taylor. However, there’s a third option: independent Greg Orman. And a recent PPP survey indicates that Orman could beat Roberts one-on-one.

This is especially interesting because in the current polling snapshot, Republicans are most likely to control 50 or 51 seats. But what if a seat that is >90% likely to go red were suddenly to go to an independent? Check out the rest of the story here. (Then comment below.)

Update: I have more comments below:  [

→ 8 CommentsTags: 2014 Election · Senate

GOP governors pay a price for blocking the ACA

August 22nd, 2014, 9:36pm by Sam Wang

It’s a part of the GOP mantra to oppose the Affordable Care Act (also known as Obamacare) in all its forms. But does that pay off at the local level? I’ve been analyzing governor’s races around the country, and I found a surprise. I wrote about it today for The New Yorker.

→ 12 CommentsTags: 2014 Election · Politics

A wave election…or a ripple?

August 19th, 2014, 2:00pm by Sam Wang

The chairman of the National Republican Campaign Committee is confident that this November he expects a wave election. Is this true…or political trash talk? I weigh in at The New Yorker. It’s my first piece for them. Check it out!

→ 13 CommentsTags: 2014 Election · House · Politics · Senate

Why you’re wrong to get excited about “60%”

August 4th, 2014, 2:35pm by Sam Wang

Some people are excited (positively or negatively) about Nate Silver’s column today giving a probability of a GOP takeover at 60%. To cut to the chase: I do not think that number means what you think it does. [Read more →]

→ 32 CommentsTags: 2014 Election · Senate

And then there were…four?

July 30th, 2014, 4:33pm by Sam Wang

Of the 36 Senate seats up for election, up to nine of them have been worth watching closely. These races will determine who controls the Senate. Over the last month a few seem to have dropped out of consideration. Now, with a new burst of polling, the playing field – at least for now – includes as few as four races. These races, plus a few others, will be crushed by attention.

The new polls, from YouGov/NYT and other organizations, confirm what I’ve said and hinted at: Georgia might be moving out of the competitive range (toward the GOP), and maybe Alaska too (toward the Democrats). That would leave four competitive Senate races. In an election held today, there is an 85% probability that each side would have between 49 and 51 votes; much of that probability is concentrated in a perfect 50-50 split.

Only four races - Kentucky, Iowa, Louisiana, and Colorado – have no clear leader at the moment. If we assign all the other races, that gives 48 Democrats/Independents and 48 Republicans.

Here is where key races stand today. Note the return of Jerseyvotes, which I’ll explain in a moment.

State Median margin Jerseyvotes
Kentucky McConnell +2.0±1.3% 100
Iowa Tie 69
Louisiana Tie 55
Alaska Begich +5.0±6.0% 52
Arkansas Cotton +4.0±1.3% 41
Colorado Udall +1.0±1.8% 28
Montana Daines +7.0±0.7% 1.2
Georgia Perdue +6.0±2.0% 0.8
Michigan Peters +5.5±0.9% 0.4
North Carolina Hagan +7.0±2.7% <0.1

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→ 22 CommentsTags: 2014 Election · Senate

With Perdue in, Nunn now an underdog (GA-Sen)

July 23rd, 2014, 11:08am by Sam Wang

Nate Cohn chose today to drop his story on how demographic trends bring Georgia surprisingly within reach for Democrats. I guess that is true, but the timing is funny. The race was close to begin with, and then yesterday’s primary was a boost for the GOP. In my view, that is the real story.

Like many, I expected Rep. Jack Kingston to be the Republican nominee in the Georgia Senate race. But businessman David Perdue bested him by about 1 percentage point. This was a substantial miss for polls, which showed a median 5.5-point lead for Kingston. However, that is par for the course for primary-season polls (dissected here). It is hard to predict which partisans will turn out.

However, general-election polls are more reliable in the aggregate. What they tell us is that the Democratic candidate, Michelle Nunn, probably got the toughest opponent possible for November. Out of six survey organizations who polled Georgia in 2014, only one gave Kingston a lead over Nunn (median margin, Nunn +2.0±2.9%). In contrast, three out of six gave a lead to Perdue over Nunn (median margin, Perdue +1.5±2.9%). That means Perdue is a stronger candidate, by 3.5% in the general election. (Note that there is a small chance, 1 in 10, that actually Kingston is stronger.)

To back up a bit, Nunn’s chances in November are still not that bad. Perdue, despite being cousin to a two-term governor, is himself new to running for office. He could make another misstep, like denigrating people who “just” went to high school. But all the same, voters coalesce around their nominee after the primary season. In the coming weeks, we should expect movement toward Perdue. At this point I would call Nunn the underdog, by a small margin.

This season, the Republican party has mostly picked their strongest Senate candidates during the primary season: Mississippi (Senator Thad Cochran over Tea Partyite Chris McDaniel) and Alaska (Dan Sullivan over Mead Treadwell). Georgia adds to that list. The one misstep has been Iowa, where Mark Jacobs probably would have been a better choice than Joni Ernst, who subscribes to fringe ideas like the threat of United Nations Agenda 21. Tea Party-like Republicans aren’t a major factor in the 2014 Senate campaign. However, they are keeping the GOP in line, both in agenda and tone. This is more apparent in the House, where they continue to go after – and win – nominations in heavily Republican districts. Whatever happens in November, we will have pretty much the same Republican party next year.

→ 20 CommentsTags: 2014 Election · Senate

Just how close is the 2014 Senate race?

July 18th, 2014, 4:06pm by Sam Wang

In my last update, some of you commented that the 2014 Senate race had swung by a lot since May. That is not true! I think perceptions were colored by my emphasis on the snapshot probability. Today, let me take a different tack.

This year, control of the Senate will be closely fought. At the moment, the 2014 Senate race is as close as the 2004 Presidential race (Kerry v. Bush). In an election held today, Democrats/Independents would probably win 48, 49, or 50 seats. There are large distinctions between these outcomes!

We’re building the data pipeline. We’ve now hard-coded our rule for collecting polls (I’ll describe the rule in comments). This allows us to plot how the daily Senate snapshot has evolved. Changes have been quite subtle:

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→ 19 CommentsTags: 2004 Election · 2014 Election · President · Senate

Senate control: Three factors to watch in 2014

July 14th, 2014, 4:22pm by Sam Wang

Here (in beta-test version) is the Senate polling snapshot for this year so far.

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→ 22 CommentsTags: 2014 Election · Senate