I strongly suspect that she is staying in the race not just because she is delusional. I think it is also because she is a Lefty Trojan horse.
NO conservative likes her at all, and few would hold their noses and vote for her. Thus, she would be easy pickings for Biden in the general. And Leftists would love it–They either get a senile old Lefty doof who is 100% controlled by the Democrat machine or they get a Lefty shill who will utterly discredit Conservatism.
It’s a win-win for them!