With Trump not currently doing all that well in the polls at the moment, there has been occasional chatter that maybe we’re not just looking at a Trump loss, but a Clinton landslide.

But what exactly is a landslide? There isn’t a really precise definition. Wikipedia says “A landslide victory is an electoral victory in a political system, when one candidate or party receives an overwhelming majority of the votes or seats in the elected body, thus all but utterly eliminating the opponents.”

That’s nice, but not very mathematical. I suppose you could define it in terms of absolute numbers “Landslide is over 80% of the vote” or something like that. But I think you should look in terms of the results in comparison to other elections.

So let me take a shot at defining a landslide in terms of being in the top X% of the elections in terms of the margin of victory. I figured I’d look at US presidential elections and what that would look like at 5%, 10%, 15% and 20%.

Or course there are also two ways of looking at US Presidential elections, by popular vote and by electoral college. So lets look at both. I’ll rank by simple percentage margin, so (winner-loser)/total.

**Popular Vote**

2016 will be the 49th presidential election where there was a popular vote tally (since 1824)

- 5% biggest wins would be the top 2. Margin to be a landslide = 25.22% (Coolidge 1924)
- 10% biggest wins would be the top 4. Margin to be a landslide = 23.14% (Nixon 1972)
- 15% biggest wins would be the top 7. Margin to be a landslide = 18.21% (Reagan 1984)
- 20% biggest wins would be the top 9. Margin to be a landslide = 17.76% (Roosevelt 1932)

**Electoral College**

2016 will be the 54th presidential election with an electoral vote tally under the 12th amendment (since 1804)

- 5% biggest wins would be the top 2. Margin to be a landslide = 97.0% (Roosevelt 1936)
- 10% biggest wins would be the top 5. Margin to be a landslide = 84.1% (Jefferson 1804)
- 15% biggest wins would be the top 8. Margin to be a landslide = 80.7% (Johnson 1964)
- 20% biggest wins would be the top 10. Margin to be a landslide = 72.3% (Eisenhower 1956)

**Clinton vs Trump**

As of right now (August 12th), estimating via current polls:

Popular Vote margin (using Pollster.com average) = Clinton by 7.7%. This would rank as #25 out of 49. Almost exactly in the middle.

Electoral Vote margin (using Election Graphs expected case) = Clinton by 188/538 = 34.9%. This would rank as #32 out of 54. Just below the middle.

If current margins hold, neither of these measures are even close to being in the top 20% in terms of how big a victory it would be. Really, it looks more like it is pretty close to a median win, with about half of elections being bigger wins, and about half being closer.

Now, we have 88 days left. In a normal election we would expect it would probably get tighter between now and November. With Trump being Trump, maybe it will go the other way a bit further.

But Clinton’s lead would have to increase by a LOT to make this election rank with the big landslides of the past.

Some people have argued that with today’s highly polarized landscape, we need to redefine landslide downward, so a much smaller win can be called a landslide. While many people may indeed end up doing that if Clinton wins by the kinds of margins seen above, I think this is silly. A win that is right near the median historically is not a landslide. Sorry.

The truth is just that we are in a time where the public is relatively closely divided… which means the environment is not very conducive to a true landslide win. Given where we are, winning the popular vote by over 7%, or the electoral college by over 180 electoral votes, may indeed be a very impressive achievement. A bigger win than might be expected even.

But it isn’t a landslide.

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Thank you for throwing some sanity on all the “landslide” hubbub. Can you please post a link to the tables of win margin by popular vote and electoral college? I’m particularly curious how well the popular vote margin correlates with the electoral college margin.

Hi Ben! Links to tables of the popular vote and electoral college vote margins are included in the article above. The Wikipedia page calculates the normalized margin for the electoral college a bit differently… they show the margin above 50% rather than the margin between the winner and runner up… but all the raw data is there. I don’t have a chart handy showing the correlation between popular vote margin and electoral college margin handy, but it should be easy to generate that from the data on those Wikipedia pages.

Thanks. I somehow missed that those were links to the data. I’ll run a regression on those.

Your mathematical definition of landslide is interesting to me since I’ve seen a couple articles saying Clinton needs a “landslide” to make sure Trumpism can’t live on in the future as a new “America First” third-party.

By the way, kudos to you for staying level-headed. I’m still not seeing other statisticians saying that this is NOT a historic landslide. I guess extremes are more exciting. Even 538 went a little crazy showing maps of what a Clinton landslide might look like.

Your question left me wanting to do the graph too. I just have a few other things to do today. :-) But you may still end up seeing an electoral vote margin vs popular vote margin chart here in the next few days. :-)

The “landslide” views people are showing take the current situation, then move everything quite a few percent further toward Clinton. Which yes, of course, if you change Clinton’s lead from an 8% popular vote lead to an 18% popular vote lead, things start to look very different, and then maybe we have a real landslide. But that isn’t where things are right now.

Posted the chart showing the popular vote margin vs electoral vote margin relationship… http://www.abulsme.com/2016/08/16/popular-vote-margin-vs-electoral-college-margin/

I think the term ” landslide ” must also include the state houses and governors,and both house and senate races in the US congress. A president could theoretically win by 80%, but if all the down ballot races went the other way and this President had no “coattails” I don’t think you can really call that 80% a landslide. On the other hand, if a President wins by 52% and both houses flip and the other side loses 8 governors and a bunch of state houses, how is that not a landslide?

Sorry i didn’t see this for awhile. Cammosutra, what you are describing is usually called a “wave” election, which is a bit different than a landslide, although they often come together.

https://en.wikipedia.org/wiki/Wave_election

Both of these terms don’t have good solid definitions though, and basically get used when people feel like using them. My attempt above was to put it into a historical context for “big wins”.