If Prop 30 fails Tuesday, counties are asking how they are going to be able to afford expenses related to realignment.
"If the money goes away, it's going to have a dramatic impact on the way we do business," California State Sherriff's Association spokesperson Sheriff Keith Royal said.
Lawmakers have a history of taking money from one program to pay for another. Constitutional protection means politicians can't touch the funds at all unless it goes back to the voters.
The next two budget years already show counties will get more than $6 billion in each of those years to take on new inmates.
"The funding stream will still continue under statute if Proposition 30 is not approved," California Finance Department spokesperson H.D. Palmer said.
But it's after that that worries county officials.
"Priorities change, legislators may change, governors may change; and right now, we're at the whim, so to speak, of the legislative process," California State Association of Counties spokesperson Mike McGowan said.
Without state money guaranteed under Prop 30, counties might have to cutback in other ways to maintain their inmate responsibilities, like rehab programs.
"We're going to see a major reduction in deputies, police officers on the street, which would then impact public safety," Royal said.
Poll numbers show Prop 30 remains a very tight race.