The Liberty Union Party, organized only in Vermont, has been running nominees for Vermont state office for 50 continuous years, starting in 1970. But in 2020, it has no nominees, other than Gloria La Riva for President.
The only minor parties in any state in the U.S. which have been on the ballot continuously for a longer period are the Conservative Party of New York (which had its first nominees in 1962), and the American Independent Party of California (1968).
1970 LU folks all passed on ???
ANY 18th Amdt 1919 booze Prohibition folks still around ???
Peter Diamondstone died.
In 1984, Diamondstone passed out anti-Sanders flyers, calling him a “Quisling” and criticizing him for endorsing Democratic presidential nominee Walter Mondale. He did not endorse Sanders’ 2016 presidential candidacy and referred to him as a war criminal for supporting the 1999 NATO bombing of Yugoslavia.
Peter Diamondstone did die back in 2017, though Liberty Union ran candidates in 2018 without much problem. That said, the core members of Liberty Union are mostly of the same generation as Diamondstone so their activity is likely declining as they reach their 80s and beyond.
Not sure I see the raison d’etre of the Liberty Union Party beyond providing a ballot access line to the Party for Socialism & Liberation when you compare their electoral activities to the more successful Vermont Progressive Party.