Florida.
Andrew Appel takes us on a tour of the selectively bizarre design decisions that have plagued Florida voters since 2000, when the infamous butterfly ballots allowed GW Bush to steal the presidency from Al Gore, all the way up to this month's election, when Broward County's standards-noncompliant ballots caused 26,000 voters to fail to cast a ballot for a contested Senate race where the current margin of victory is 12,562 votes.
Amazingly, though Florida's ballots are consistently terrible design catastrophes, they are also consistently design catastrophes that penalize Democratic candidates, which is the most amazing coincidence, ever.
By the way, if you're not sure which party those 26,000 voters might have intended to vote for in the Senate race, look again at Broward ballot. In the race right below the Senate race, one party didn't even nominate a candidate to run in that Congressional district.
Florida is the Florida of ballot-design mistakes [Andrew Appel/Freedom to Tinker]