I can’t think of any historical parallel.
The Shakers don’t really come close, but they were a celibate religious sect that adopted orphan children to create the next generation of Shakers. Eventually, that just wasn’t enough to keep things going. There are 3 of them left. Which, in political terms, is not enough to win an election.
There are 3 because they just took in a 59 year convert. She is the youngest.