Written by John Lounsbury
We have recently examined on how few votes the outcome of a close election can swing. We showed how a shift of a little over 200,000 votes from Obama to Romney would have reversed the outcome of the 2012 election. See Why National Polls Mean Little In U.S. Presidential Elections.
We have previously shown how small shifts in 2012 voting patterns could create a Clinton electoral college win while she hypothetically received fewer popular votes than Trump; and the reverse with Trump becoming president with fewer popular votes than his major opponent.
But, what about a landslide? Two weeks ago opinion polls indicated a race “too close to call”. Then, in a matter of days the polls shifted to indicate Clinton with a lead well outside of the sampling error uncertainty. That is how quickly things can change – and they could change in the reverse direction from the recent Clinton surge.
What could cause big changes? Here are some possible events:
Donald Trump’s mouth
Further Clinton email revelations
Private communications revealing previously unknown facts about Trump
Major health issue with either candidate
Sudden economic downturn
Stock market decline of more than 10%
Significant terror attacks inside the U.S.
Surge in support for one or more ‘third party’ candidates
There are very likely more possibilities we haven’t mentioned, but you get the idea.
As we have for previous hypothetical discussions we will work from a baseline of the 2012 presidential voting results. The table is from Wikipedia:
In the following we will assume the effects considered occur by the same percentage amount for every state. This is obviously not realistic; an affect might occur with a magnitude of 2% in some states and 10% in others. We will simply use the over-simplified average identical for every state to show an affect for a relatively low vote shift. To start applying different percentages to each state make an unnecessarily complex discussion.
Hypothetical #1: A Trump Landslide
Two ways this could occur:
Third party candidates take 2% more from Clinton than from Trump.
There is a 2% voting shift from Clinton to Trump.
Both shifts are from the 2012 voting totals.
The electoral vote margin for Trump becomes 305-233 as the following states flip from blue to red: Colorado, Florida, Iowa, New Hampshire, Ohio, Pennsylvania and Virginia.
This is a comfortable margin even though Clinton would have a slight popular vote margin plurality.
If the 2% above is changed to 3% we add the following states flipping to red: Maine (2nd), Minnesota, Nevada, New Mexico and Wisconsin and Trump’s electoral college margin becomes becomes 337-201 and he has a plurality of the popular vote. This is near landslide, but arguably not quite there.
If the switch is 5%, the states of Michigan and Oregon and added to the Trump column and the electoral margin becomes 360-178 and we can start to call the election a landslide.
Hypothetical #2: A Clinton Landslide
We will just reverse the 2% shift across ther board from the 2012 results.
Only one state flips from red to blue: North Carolina. Clinton’s electoral college margin would be 347-191. Perhaps a very skimpy landslide? Or not.
Reversing by 3% produces the same change as for 2%
But at 5% vote shift the following additional states go from red to blue: Alaska, Arizona, Georgia, Indian, Missouri, Nebraska (2nd) and South Carolina. The electoral college margin would be 398-138 which gets into landslide territory.
Conclusion
The current election appears to be headed for a significant shift in voting patterns. A shift of only a few percentage points in favor of either candidate could turn the recent pattern of close elections into a landslide. And, as we discussed earlier, there are some factors at play this year which could blow either campaign off the course that has been planned.
For those who may question whether third party candidates could have the size of impact that we are discussing, since 1800 32% of presidential elections (17) had significant third party voting which averaged 10% of the total vote. Five of these had greater than 15% and two were over 20%. Teddy Roosevelt (2012) received 29.6% of the vote and pushed one of the major party candidates into third place. See History Of ‘Third Party’ Presidential Candidates.
