I’ve always estimated The Dead Dog vote to be 24%.
If you are an unknown who puts your name on the ballot in a head to head primary against an incumbent and does nothing, and the incumbent does nothing, you are going to get 24%
Unknown Gail Goode, who shot her wad getting on the ballot, and whose campaign after that consisted mostly of hanging literature on light poles, got 24% in the Democratic primary for United States Senate.
A Dead Dog would get 24%. Hence the name.
But the Dead Dog vote is not a floor; one can blow even that.
It was 1996 and Brooklyn Democrats were engaged in one of the meaningless wars that gets them so animated (in contrast to, say, general elections for POTUS, which they regard as days off from political activity, unless they are sending troops out of town, or, like Dov Hikind, they are busy working for the Republicans).