While a last-minute change like Louisiana’s is highly unusual, states have broad autonomy to define the timing and procedures for primary elections. The exact process for setting primary dates varies from state to state. Could the general election be postponed or canceled? The date of the general election is set by federal law and has been fixed since 1845. That would mean legislation enacted by Congress, signed by the president and subject to challenge in the courts.

Source: New York Times March 14, 2020 12:00 UTC