As of January 31, 2021, here are registration totals for South Dakota: Republican 279,921; Democratic 158,697; Libertarian 2,429; Constitution 438; independent and miscellaneous 141,237. Percentages are: Republican 48.04%; Democratic 27.23%; Libertarian .42%; Constitution .08%; independent and miscellaneous 24.24%.

On October 12, 2020, the percentages were: Republican 48.02%; Democratic 27.58%; Libertarian .39%; Constitution .06%; independent and miscellaneous 23.95%.

The Constitution Party is not ballot-qualified, but South Dakota lets parties that lose their qualified status keep and expand their registration.