For the past 43 elections (i.e., starting in 1852), the winner of every presidential election has been a Republican or a Democrat. For the past 27 elections (i.e., starting in 1916), even the runner-up has belonged to one of these two parties. These parties' combined share of the popular vote has averaged about 95% for the past 100 years.
Yet surveys often find that large numbers of Americans say they'd like another party to emerge. Political independents in the US are a famously heterogeneous demographic, so coalescence around a single candidate may be unlikely. But the combined votes for all so-called "third-party candidates" has sometimes driven the Dem + Rep share to below 90%.
What percentage of the US 2024 presidential popular vote will the Democratic and Republican parties (combined) receive?
This resolves as the sum of all votes for the Republican Party or Democratic Party nominees in the 2024 US presidential election, divided by the total number of votes. The value is in percentage points. So a prediction of 95.7 means the Dem + Rep share is 95.7%.