Well...
[SNIP TWEET - Low 30,211; Simitian 30,210]
That’s a .0002% difference. This would make it possibly the closest election in world history. The Wikipedia article only has single winner elections and for those it’s the 1974 NH-Sen with .009% or two votes.
That would be 0.0017% rounded to 2sf. All below figures are two-party-preferred, as the Aussies would have it.
On Good Friday, Ballotpedia
helpfully reminded us that the closest ballot measure in California history was decided 92,558-92,556, in favour of
increasing elected official salaries in 1908. The margin there was 0.0011%; unless this comes out as a tie, there's no beating that.
I reminded all of you about Mark Oaten's case in the thread on the
Caddo Parish sheriff race (21,621-21,620; 0.0023% margin). Oaten, a Liberal Democrat, won 26,100 votes to his Conservative challenger's 26,098. The 0.0038% margin there was close enough to force a revote after various allegations surrounding the 1997 General Election vote in his Winchester constituency - which he won by a much vaster margin.
Michelle Gildernew, the Sinn Fein MP from Fermanagh and South Tyrone, is the undisputed queen of close elections; she's had a few in her time but most notably held off a unionist opponent 21,304-21,300 in the 2010 General Election. That brings that level-ish with NH-SEN-1974 and the infamous FL-PRES-2000 vote.
The closest constituency in Ghana's frankly ridiculous 2020 general election was Sene West. The NDC incumbent won 13,116-13,100 against his NPP challenger (the wonderfully-named independent Caesar Fomeka conquered 191 ballots), a 0.061% margin. Had it or any other constituency flipped, there would be a parliamentary majority, although luckily for the NPP and Nana Akufo-Addo, an ex-NPP independent won the critical seat #138. Still a crushing victory compared to everything else on this list, though.
TL;DR:SCA 14 (California 1908): 0.0011% margin
Simitian-Low 2024: was 0.0017% margin; now wideningCaddo Parish 2023: 0.0023% margin
Winchester 1997 (UKGE): 0.0038% margin
Florida 2000 (Presidential): 0.0092% margin
Fermanagh and South Tyrone 2010 (UKGE): 0.0094% margin
Sene West 2020 (GHGE): 0.061% margin
