The American Delta Party, which was formed in a few states in 2016 by Rocky De La Fuente, no longer has enough registered voters in Delaware to be ballot-qualified. Delaware had been the only state in which the party was still on the ballot.
However, it is still possible for it to regain status in time for the 2020 election. Here is a link to the January 2, 2020 data, showing that parties need 715 registered members. American Delta now has 711.