That's code for "we want to jack up your taxes."
After Prop 13 passed, taxes were frozen at 1% of the property value at the time 13 passed. Properties were re-assessed when they were sold. Each year there is an inflation factor which increases all property values.
With the high level of home sales in CA, and the high rate of home price increase, cities and counties have done very well under Prop 13. But no, there liberals want homeowners to be paying twice as much in taxes so they can spend twice as much.