The Butterfly Ballot
2000 Presidential Election in Palm Beach, Florida
In the 2000 election, Palm Beach County was using a hole-punch voting machine with a single column of holes. Hole-punch ballots are inherently error-prone in multiple ways, but this was compounded by a layout design error.
Most offices had 2-5 candidates; the names could all fit on one side of the punch with lots of space between holes. However, the Presidential election requires listing both the candidate & their Vice President running-mate, and furthermore 10 parties qualified for the ballot.

The local Board of Elections handled this by alternating entries on either side of the hole punch, with a design compared to butterfly wings. The first six parties were staggered down the left side using the odd-numbered holes. The right side of the ballot held the remaining tickets (and a write-in space) and aligned with the even-numbered holes.
- Bush (1st ticket on the left)
- Buchanan (1st on the right)
- Gore (2nd on the left)
etc.
Compared to other parts of Florida, a highly disproportionate number of Palm Beach ballots were either cast for Buchanan, or disqualified for over-voting both Buchanan & Gore. Academic studies suggest that about 2000 Gore supporters miscast their vote for Buchanan, and even more over-voted.
How important was this mistake? Well, Bush's final margin of victory in Florida was only 537 votes. An additional 2000+ votes in Gore's favor would have easily tipped Florida, and due to USA's unusual "Electoral College" system, would also tip the nationwide result.
BTW, the same disproportionate error had occurred in the 1996 election, costing a similar number of votes for Bob Dole, but that election wasn't close so no one bothered to investigate it went mostly ignored until after 2000.