On election night you trade the race live as results come in, using your own county-level model that knows the expected vote share and reporting order for each area. When early returns look scary or rosy, you judge whether Polymarket is over- or under-reacting given which places have actually reported. The edge is interpreting partial returns faster and more accurately than the panicking crowd, which requires acting in seconds via a pre-built decision tree.
Markets on Polymarket where election-night live trading is the natural play: