The Aggregated 2016 Electoral Map
One week to go!
Hillary Clinton has a strong electoral lead — 347 to 191 — and she is close in a few states where Donald Trump leads, such as Georgia and Missouri. Consistent with polls and the election narrative, Clinton is en route to handing Trump a resounding electoral loss.
Here’s the predicted 2016 electoral map:
The below table shows current projections for battleground and other close states in the 2016 electoral map.
|State||Clinton||Trump||Johnson||Stein||Clinton Chance of Winning||Trump Chance of Winning|
Structural Model Method
Independent of candidate characteristics, the Republican Party should fare well in 2016 due to Democratic Party fatigue (only once since 1952 has the same party held the White House for more than 8 years in a row). However, Donald Trump’s historically low favorability ratings may very well cost him the presidency — including candidate favorability in the structural model hurts Trump to the tune of 60 electoral votes, enough to flip the election from a close Republican victory to a Clinton rout.
The structural model takes data from the 2000, 2004, 2008, and 2012 presidential elections to run a linear regression that determines the relationship between a handful of variables, including state demographics, and number of Democratic public officials, and the Democratic vote share. It is developed by averaging two approaches: one which ignores candidate favorability and a second which includes in the regression the difference between Hillary Clinton and Donald Trump’s net favorability (the results from those models can be found here and here. Clearly, Trump’s historically low favorability ratings could potentially cost him the election).
The structural model assesses the underlying electoral landscape separate from campaign actions. By accounting for factors such as the state partisan voter index (developed by the Cook Political Report), the percent of House seats occupied by a Democrat, and region, we can understand how states are inclined to vote without campaign activities or candidate quirks. Of course, considering Clinton and Trump have high unfavorable ratings, a pure structural analysis will likely miss the mark (hence averaging it with a structural model that includes favorability). We have also developed a state battleground model to analyze poll results.
The structural model serves as a baseline. We can expect these, or similar, results if the campaign ended today. Between now and November 8, one variable will be adjusted: the difference between Clinton and Trump’s net favorabilities. Numbers are from Gallup.
Overall, the model explains around 94 percent of the vote share variation during the four elections.
Predicting third party candidate vote shares is difficult because they fared poorly in previous elections, but polls indicate 2016 will be different. Regression models won’t work. Instead, using a Libertarian and Green Voter Index, vote shares for Gary Johnson and Jill Stein can be modeled. The voter indices approximate each state’s inclination to vote for a Libertarian/Green Party candidate by taking state results from the past four elections and dividing them by the LP/GP national result. This index can then be multiplied by Johnson and Stein’s national polling average to estimate their vote share in any given state.
An example should clarify the method (the following numbers are all made up): Say in Alabama the Libertarian candidate received 0.5% in 2000, 0.25% in 2004, 1% in 2008, and 2% in 2012. Nationally, that candidate earned 1% in 2000, .50% in 2004, 1.5% in 2008, and 3% in 2012. The index for each year is 0.5, 0.5, .67, and .67. Averaging the four, Alabama would have a Libertarian Vote Index value of 0.59. To estimate Gary Johnson’s 2016 vote share in Alabama, I multiple 0.59 by his national polling average (which I have weighted to account for pollster accuracy and date).
With a Libertarian and Green Party candidate included, Clinton and Trump vote shares need to be adjusted. To determine how much to subtract from each, I find the difference in polling averages between the weighted Clinton vs. Trump average and the weighted Clinton vs. Trump vs. Johnson vs. Stein polling averages. From there, I divide the difference between each candidate’s polling average by the total number of percentage points lost between Clinton and Trump. Their initial vote share estimates are then subtracted from the difference quotient multiplied by expected Johnson and Stein vote shares.
These values will obviously change as Johnson and Stein’s poll numbers fluctuate and the difference between the two polling averages changes. As such, this model will be updated weekly (assuming new polls are released during the week).
State Poll Method
This model is developed through a simple process: Take the cross-tabs of each state poll and look at response by race, gender, and party identification. Those results are multiplied by inferred electoral composition of each group (determined by a linear extension of the trends displayed in 2004, 2008, and 2012). Demographic breakdown (race, gender, and party ID) is averaged and then multiplied by pollster rating (numeric values assigned based on the 538 assessment of polling outlets) and 1 divided by the days until the election from the poll’s end (this means that recent polls are weighted more than older polls). Results are then multiplied so the numbers are sensible (ie, so that when added together, the numbers are equal to the sum of poll values in the RealClearPolitics average).
This model aggregates and weights the structural and state poll maps. Initially, the two are weighted equally, but as states are polled more and election day nears, the battleground states model is dynamically given a larger say in the aggregate. The structural model without candidate favorability sheds weight faster than does the structural model that includes candidate favorability.
To determine win probabilities, each state’s expected vote tally is simulated 1,000,000 times, varying candidate strength among different races, gender, party, and expected third party vote. Doing so allows the model to account for polling error — by varying strength among demographic subgroups, the model analyzes what might happen if Clinton or Trump fares, for instance, unexpectedly well with black voters (an outcome that could flip Georgia to Clinton or allow Trump to win Pennsylvania).
July 20 Update: Our model continues to favor Hillary Clinton though polls, national and state, are beginning to tighten. The structural model, which accounts for candidate favorability, gives Clinton a large edge. Clinton’s unfavorable ratings have risen whereas Trump, with the aid of the Republican National Convention, saw his favorable ratings rise a couple of points. However, Clinton’s margins in state polls, while shrinking, when combined with the structural model yields a comfortable lead. Neither candidate is consistently crossing 45% in state polls, a clear sign that voters are dissatisfied with their choices this November.
Is Indiana in play? The model saw Clinton’s chances in Indiana skyrocket this past week. Can she actually compete in the traditionally red state? Most likely not, though Trump’s selection of Indiana Governor Mike Pence as his running mate and joint rally in that state, plus his commitment to spending money defending the state’s 11 electoral votes, indicates that the Trump campaign might not be comfortable in its slim lead there. Indiana’s past proclivity to vote for a libertarian candidate leads to a high expected result for Gary Johnson in the state. Our models show that when Johnson is included in national polls, Trump loses slightly more support than does Clinton. Those two instances intimate a close race in Indiana, one which might not bear fruit in November. State polls are needed.
How might the RNC affect the race? It’s too soon for polls to reflect Trump gains from the RNC, though his net favorability, tracked by Gallup, has risen throughout the week. Polls released over the weekend and the beginning of the next week will likely show a closer race, with the Democratic National Convention next week similarly giving Clinton a bump. In the weeks after the conventions polls should stabilize and begin to reflect the true nature of the race.
June 29 update: In the last week, Donald Trump’s net favorability numbers rose by around 4 points while Hillary Clinton’s fell by the same amount. That net differential helped Trump gain a couple of points in the structural model, narrowing Clinton’s lead in Florida, Ohio, and Iowa and allowing Trump to expand his margin in Indiana and Missouri to double digits.
North Carolina remains in Trump’s corner by a couple points. Georgia and Arizona, two states Clinton supporters think might turn blue this cycle, both favor Trump by 9 points. Here the state polls differ from the structural model: Our state poll model shows Trump three points in the Copper State, but the structural model gives him a larger edge.
July 6 update: The holiday weekend meant few polls released this past week. National numbers continue to strongly favor Hillary Clinton and state polls largely back up that data (though more are needed). This next week will be interesting as polls will capture the effects of Donald Trump’s latest Twitter snafu and the potential fallout from Clinton’s email investigation conclusion.
North Carolina is currently anyone’s game, as evidenced by Clinton campaigning there with President Barack Obama and Trump holding a rally in the state that same night. Other efforts to expand the electoral map, for both campaigns, are not yet looking good. Arizona and Georgia, two states in which some Clinton folks believe she will be competitive, still strongly back Trump; Wisconsin and Pennsylvania, states Trump believes he can flip, are pro-Clinton at this time. Ohio remains very close and Nevada, while still favoring Clinton, is showing a very tight race in state polls.
Gary Johnson is still forecasted to do well for a third-party candidate. His national numbers are approaching double digits, though his state polling is rather low (or non-existent — a number of surveys fail to include his name). Currently, third-party candidates actually hurt Clinton more than Trump, perhaps indicating that a few points of her support comes strictly from people voting against Trump (not for Clinton).
July 13 update: North Carolina has flipped from slightly favoring Donald Trump to favoring Hillary Clinton by a percentage point. The state’s 15 electoral votes put Clinton at 347 and Trump at 191. Aside from Indiana, which has tightened this week as Trump (and Clinton’s) favorability dipped, this map is the same as the 2008 electoral map.
In recent days, national and state polls have reflected a close race. Contemporary Quinnipiac University polls show tight, if not tied, races in Ohio, Pennsylvania, and Florida. Our models, which look at weighted and aggregated polls, still show Clinton with a slim lead in those states and a likely victory. That said, if the polls continue to show a close race in said states, our model will quickly reflect the new reality.
Heading into Cleveland, Trump must try to further unite his party. He currently receives between 70 and 90% of the Republican vote in most states whereas Clinton generally receives 80-95% of the Democratic vote. Trump must boost his numbers among Republicans; he still has room to grow in that area. Clinton has yet to reach her ceiling among independents, a number of whom likely supported Bernie Sanders in the primary and are still making their way to the Clinton camp. Sanders’ recent endorsement of Clinton may hasten that process.
Some fallout from Clinton’s email scandal has been noted. Her favorability numbers declined this week and polls post-James Comey’s decision not to recommend charges have shown her shedding a couple of points to Trump. However, it doesn’t seem like Trump successfully capitalized on the announcement. Time will tell whether he can keep salient Clinton’s email scandal.
The Republican Convention will likely boost Trump’s poll numbers a little bit. That likely won’t be reflected next week, but rather during the week of the Democratic National Convention. Trump unveiling his vice-president might also pad his numbers among Republicans. As summer wears on, the excitement continues — check back next week for the updated model!