How many ways can an Electoral College tie happen?

POTUS election season is officially upon us and it has gotten me to wondering something. How many ways are there (if any) to make a perfect tie in the Electoral College, 269-269? How would you write an equation/logorithm for it and how would you figure that out on paper?

It's a great problem and well-known in CS circles: Partition Problem on WikiPedia.
There are several algorithms to do it, especially in this case where the sizes of the inputs (state electoral votes) are bounded.

Quote: MathExtremist

It's a great problem and well-known in CS circles: Partition Problem on WikiPedia.
There are several algorithms to do it, especially in this case where the sizes of the inputs (state electoral votes) are bounded.

I'll check it out. I wonder what the odds of it happpening are if say you eliminate all the red/blue states from toss-up based on say how they have voted since say 1996? (ie: always red or blue since then it cannot be a toss-up.)

Yeah AZ, there are some states you should be able to safely 'eliminate' as they are safely red or blue.

When you find a tie scenario, then the next step is to look at Congress as each state delegation gets one vote. :)

Quote: AZDuffman

POTUS election season is officially upon us and it has gotten me to wondering something. How many ways are there (if any) to make a perfect tie in the Electoral College, 269-269? How would you write an equation/logorithm for it and how would you figure that out on paper?

It's important to remember that the election goes to the house not because of a tie, but because no one wins a majority.

The theoretical number of ways to do it is fairly large, but there is still a fair subset which is possible using only battleground states. However, a third party candidate that wins 2 or 3 states could easily deprive someone of the majority. In that case the Republican candidate should win, given their majority in the House.

I remember in 2008, before Obama got his big surge near the end of the campaign, that I found at least four possibilities for a tie using only battleground states.


Presidential of 1968 when Wallace took 5 states, had Nixon lost some of the northeastern states and Michigan (which he would have lost today), it would have still gone to the House even though he had a large plurality of Humphrey.

Trump could be the spoiler in 2012. He could take 1 or 2 states and throw it into the House.

Quote: AZDuffman

I'll check it out. I wonder what the odds of it happpening are if say you eliminate all the red/blue states from toss-up based on say how they have voted since say 1996? (ie: always red or blue since then it cannot be a toss-up.)

The absolute theoretical possible space has to have millions of possibilities to get you a tie of 269-269. For example, you could theoretically win only 11 states and still have 270 electoral votes. If you switch out NJ for VA then you have a 269-269 tie. There are many combinations of smaller states that add up to 13 votes that you could use to replace VA.

1 , California , 55 , 55
2 , Texas , 38 , 93
3 , Florida , 29 , 122
4 , New York , 29 , 151
5 , Pennsylvania , 20 , 171
6 , Illinois , 20 , 191
7 , Ohio , 18 , 209
8 , Georgia , 16 , 225
9 , Michigan , 16 , 241
10 , North Carolina , 15 , 256
11 , New Jersey , 14 , 270

Virginia , 13


It should be fairly easy at this stage in the election to come up with a dozen tie scenarios while still leaving the core states intact.

Obama only lost two of those 11 states in 2008, Texas and Georgia.

Here is my most likely near tie scenario.

The first assumption is that the states that voted against Obama in 2008 will continue to do so in 2012.
= That won McCain 173 electoral votes, but that would be 180 after the 2010 census if 2nd district in Nebraska goes Republican.
The second assumption is that states where Obama received less than 54.25% of the vote will go Republican.
The only exception is Minnesota, which had 54.06% of the vote for Obama in 2008. I assumed they stay with Obama.

29 Florida
18 Ohio
15 North Carolina
11 Indiana
9 Colorado
6 Iowa
1 Nebraska's 2nd district.

This theoretical election results in a near tie, with the Republicans winning 268.

Quote: pacomartin

Here is my most likely near tie scenario.

The first assumption is that the states that voted against Obama in 2008 will continue to do so in 2012.
= That won McCain 173 electoral votes, but that would be 180 after the 2010 census if 2nd district in Nebraska goes Republican.
The second assumption is that states where Obama received less than 54.25% of the vote will go Republican.
The only exception is Minnesota, which had 54.06% of the vote for Obama in 2008. I assumed they stay with Obama.

29 Florida
18 Ohio
15 North Carolina
11 Indiana
9 Colorado
6 Iowa
1 Nebraska's 2nd district.

This theoretical election results in a near tie, with the Republicans winning 268.

IMO, there are a couple of other ways likelier than the NE split again. AZD, you can easily play around at 270towin.com

There's also a lot of legal questioning about whether or not the NEW House or the OLD House would vote (as states' delegations, each getting 1 vote) in the event of no electoral majority. I always thought it was the old (pre-election) House, but some have challenged me and said that only the electoral votes are counted before Christmas, and there is no set time for the House to take their vote, and it might not be immediately. Since the new House is sworn in very quickly after the New Year, it would be very interesting.

Also, I think you are close to Romney's path to victory, but I'd replace the Western States with VA and NH, which would give him 270 without the NE-split, and give us the 269-269 tie with it:

Romney wins with McCain PLUS FL/OH/NC/VA/IN/NH (and the extra NE vote). A very reasonable path to victory (all but NH were won by Bush 43 twice) that I'm sure is part of his strategy.

Personally I think Romney has a better chance of stealing a vote in Maine than Obama does in winning a vote in Nebraska again, but both would make ties even more plausible.

Quote: cclub79

Romney wins with McCain PLUS FL/OH/NC/VA/IN/NH (and the extra NE vote). A very reasonable path to victory (all but NH were won by Bush 43 twice) that I'm sure is part of his strategy.

The LA Times listed their choice (based on Gallup Poll) for the 12 battleground states. What is interesting about this list of 12 is it includes Arizona and Georgia which were lost by Obama in 2008. I personally find it hard to believe that Obama will win states in 2012 that he lost in 2008.

I am also surprised that Indiana, New Hampshire and Minnesota are not on the list.

Quote: LA Times

Obama's Gallup numbers show 12 states in play in 2012

The battlegrounds, which also appear on lists drawn up by strategists in both parties, are

three perennial swing states,
Florida (29), Ohio (18) and Pennsylvania (20);

Iowa (6);

three in the South,
Virginia (13), North Carolina (15) and Georgia (16);

and five states in the West, Oregon (7) plus a grouping in the interior West made up of
Nevada (6), Arizona (11), New Mexico (5) and Colorado (9).
For those states, Obama would have to depend on a large Latino turnout.

The Southern states would require a heavy turnout among blacks plus support from moderate-to-liberal suburban whites.