In 2023, Missouri started letting voters choose a party on the voter registration forms. The voter’s choice has no effect on how that voter is treated. Missouri continues to be an open primary state, in which any voter is free to choose any party’s primary ballot. Therefore, only 4% of voters have indicated a choice so far.

Missouri tallies registration for parties that have polled 2% of the vote at one of the two preceding elections for any statewide race. Therefore, currently there is a tally only for the Republican, Democratic and Libertarian Parties. Thanks to Jeff Coleman for this information.